I dumped Strava months ago when they changed their pricing model, and started using connect more. One thing I started doing was adding post run images to my activities. A few weeks ago it seems to have stopped working. I get the toast message at the bottom of my phone (Oops! Something went wrong while uploading your file.).
I've tried disconnecting from WIFI in case it was something local causing it, but the issue remains.
Latest Connect App available in the play store: 4.35.1
Google Pixel 3xl on Android 11 w/October patch.