This is a weird one.
I upgraded to SDK28, built a new IPA and uploaded it to TestFlight.
I upgraded via TestFlight, and TestFlight showed the new version number, but the app itself was still the previous release. TestFlight showed all up-to-date with no upgrade available.
I then uninstalled and reinstalled via TestFlight again, now it was the new release.
So TL;DR is: TestFlight upgrade didn’t work, had to uninstall to upgrade to the new version. Will my users experience the same when they upgrade to SDK28? I don’t to tell them they have to uninstall before upgrading.
EDIT: Could it be because the Expo account name changed, as I transfer it to a client’s Expo account?