Last week, Canon released a new v1.2.0 firmware update for the Canon EOS R3, as well as updates for the EOS R5 and EOS R6 mirrorless cameras. The new EOS R3 firmware brought a bunch of new features to the camera including the ability to shoot full HD video at 240fps, enhancements to timelapse shooting along with a bunch of other stuff.
A couple of days later, Canon pulled the new EOS R3 firmware as the result of a bug. A DPReview user says that they spoke to CPS UK and that if you were running v1.2.0 and performed a factory reset of the camera then the mode dial no longer worked correctly. Canon has now released a new v1.2.1 firmware update to resolve this issue.