Comment 9 for bug 1944481

Yes, I'm running into the issue above, where a windows IIS server is not correctly serving the new Let's Encrypt R3 intermediate certificate chain, signed by "ISRG Root X1", and still serving the old R3 intermediate signed by "DST Root CA X3" (which means it's going to fail for everyone else on Sept 30th.) Windows IIS server might need an update or might need to be rebooted. https://community.certifytheweb.com/t/upcoming-expiry-of-dst-root-ca-x3-and-r3-intermediate-for-lets-encrypt/1480

In the meantime, from the ubuntu point of view, how do I roll this update back? The cert is still valid for another week. `sudo apt install ca-certificates=20210119~20.04.1` says `E: Version '20210119~20.04.1' for 'ca-certificates' was not found`.