I have the same problem, and I can confirm it's very new. I was able to commission a node with an OpenVswitch bridge as late as 2022-08-10, but ran into this bug when trying to commission a new machine on 2022-08-15. Same error in the controller log. I found something interesting though. In regiond.log, it looks like maas started downloading a new kernel release ['20220810']. It seems to be the only thing that changed between 2022-08-10 and 2022-08-11. This is the first time it shows up in the logs:

2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:amd64:ga-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:amd64:ga-18.04-lowlatency: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:amd64:hwe-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:amd64:hwe-18.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:amd64:hwe-18.04-lowlatency: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:amd64:hwe-18.04-lowlatency-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:arm64:ga-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:arm64:hwe-18.04: to_add=['20220810'] to_remove=[]
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2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:arm64:xgene-uboot: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:arm64:xgene-uboot-mustang: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:armhf:ga-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:armhf:generic-lpae-generic-lpae: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:armhf:hwe-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:armhf:hwe-18.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:i386:ga-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:i386:ga-18.04-lowlatency: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:i386:hwe-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:i386:hwe-18.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:i386:hwe-18.04-lowlatency: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:i386:hwe-18.04-lowlatency-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:ppc64el:ga-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:ppc64el:hwe-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:ppc64el:hwe-18.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:s390x:ga-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:s390x:hwe-18.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:18.04:s390x:hwe-18.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:amd64:ga-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:amd64:ga-20.04-lowlatency: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:amd64:hwe-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:amd64:hwe-20.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:amd64:hwe-20.04-lowlatency: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:amd64:hwe-20.04-lowlatency-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:arm64:ga-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:arm64:hwe-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:arm64:hwe-20.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:arm64:xgene-uboot: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:arm64:xgene-uboot-mustang: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:armhf:ga-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:armhf:generic-lpae-generic-lpae: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:armhf:hwe-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:armhf:hwe-20.04-edge: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:ppc64el:ga-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:ppc64el:hwe-20.04: to_add=['20220810'] to_remove=[]
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2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:s390x:ga-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:s390x:hwe-20.04: to_add=['20220810'] to_remove=[]
2022-08-11 20:50:55 sstreams: [info] com.ubuntu.maas:stable:v3:download/com.ubuntu.maas.stable:v3:boot:20.04:s390x:hwe-20.04-edge: to_add=['20220810'] to_remove=[]