Canon has released an update to the firmware for the EOS R5 and EOS R6 cameras. Additionally it has announced that a further update will be released in late March 2022 which will optimise autofocus (AF) operations.
Firmware version 1.5.1 incorporates the following fix:
1. Fixes an
issue that in rare instances, the camera may become inoperable when
shooting in the Servo AF setting while operating the <AF-ON>
button.
The firmware update can be downloaded from Canon Support. In the packaged files that download are instructions for installation. These should be carefully followed to ensure that the firmware update is correctly installed.