Shuji at Zwift HQ. Are the images saving to Zwift? Can you see the images in your Activity feed in the Companion app or the zwift.com/feed web feed?
If yes - it’s possible this is a restriction on Strava’s end because you’re under 18. Their privacy control article for U18 accounts doesn’t mention saved images, but you might want to ask the folks at Strava too.
Random as in some images / videos within a session will save, and others from the same ride will not?
Or: zero images from a session will upload, and the next session it will work fine?
If the first: in the save screen UI where you see the thumbnail images for notable moments - check to see if there’s a greyed out icon in the upper right corner of each thumbnail. If you click on that thumbnail - the greyed out icon should darken. Try that next time you save a ride and see if that makes a difference?
I’ll pay better attention as usually I just hit save and edit strava later on. One image always has a yellow star lit and I thought that was the default highlight that was getting uploaded?
Given there doesn’t seem to be a consistent rationale for this - I’m going to suggest you do a thorough deletion of all things Zwift related, and re-install. Instructions are here - this is a more thorough removal than the usual Windows uninstall utility.
After you reinstall - go into the in game settings options and check that video screenshots is enabled.
Would you give that a try and let us know if that resolves it?