Canon R5 M-Fn and Movie Record button stops working

[jaewoosong]

I have already emailed canon support but wondering if anyone else has seen this issue and what they did to fix.

Last month when trying to record 4th of July fireworks, I noticed that my movie shooting button was not working. Firmware at the time was 1.3.1. Thinking it was a firmware issue, I waited til 1.4 came out, installed and checked to see if I had the same issue.

I have the M-fn button configured to "still <--> movie switching" and the movie shooting record button set normally to movie recording.

When the camera is turned on cold after being off for a while, both the movie shooting button and M-Fn button works to switch between still and movie. After being on for a while (I recorded video for 2 min), it stops working as expected.

When I press either the M-Fn or Record button, the switching does not work and record button. (rear display just shows black bars at top and bottom).

When I select the M-Fn to another function like "switch to custom shooting mode", both the M-Fn and Video record button perform same action.

When I select the M-Fn to another function like "lcd panel illumination", both the M-Fn and Movie shooting button starts movie recording.

I can switch between still and movie mode using the Mode/Info combo and start/stop movie recording via shutter button or movie recording button on rear display.

Below is a youtube video that shows the erratic behavior of my R5.

https://youtu.be/eUzET_iFGzI

[jaewoosong]

Just in case others see this issue, I sent the body into Canon for warranty repair and top cover assembly was broken (I never dropped/damaged this camera) and assembly was replaced.