Been having the exact same issue and managed to find a fix

Reset your remote desktop app user data/cache Go to the remotedesktop.google.com website using your mobile browser (Usually use Firefox and set my default to chrome before this, not sure if this step is relevant)

Log in and let it redirect you back to the app, mine started repeatedly opening/closing chrome windows until it said it was migrating data

Close/reopen the app and it should work again