Comment 3 for bug 2006797

There's new MT79xx firmware available from upstream kernel.org:
https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/mediatek

Copy the following files to /lib/firmware/mediatek on your machine (make backups first):
BT_RAM_CODE_MT7922_1_1_hdr.bin
BT_RAM_CODE_MT7961_1_2_hdr.bin
WIFI_MT7922_patch_mcu_1_1_hdr.bin
WIFI_RAM_CODE_MT7922_1.bin
WIFI_MT7961_patch_mcu_1_2_hdr.bin
WIFI_RAM_CODE_MT7961_1.bin

Reboot and check if that makes a difference.