Same here - build showed up for a while in App Store connect TestFlight - and after a few it's missing. I've tried twice - both the same issue.

Same issue here, tried 3 times

Same here, tried 3 times

Im having the same issue since few days. Sometimes it fails before uploading telling me "credentials invalid". I have updated all keys, profiles etc. and still same thing. Today I will try from another computer

Same here

Same here