It's a known conflict and I'm pretty sure a fix / patch needs to be created / implemented by Psyonix; it is listed, potentially twice, on the RL current known issues page:
[PC] Focus on the game client is occasionally lost
[PC] controller may randomly disconnect during gameplay
However, whilst i do not use the app, I have read a couple of posts where people have specifically disabled the Game DVR, not the whole Game Bar, worth a try. If this doesn't work, disable the Game Bar completely for a test, if you find the problem persists, then this could be the other known conflict with the W10 News and interests feed (you can disable this through the Group Policy Editor)
It's a known conflict and I'm pretty sure a fix / patch needs to be created / implemented by Psyonix
Correct. We are working on a fix for this. Further updates on this to come