I've had no issues with the app in the past few months including international travel - iPhone user as well. Visa requirements may make the workflow more error prone, though I've not gotten the Real ID reminder in a long time either so it's odd that it is still popping up in yours unless you don't have one yet?

Last international trip was in December to Japan and no issues with using the travel ready center in advance of check in - though all flights were on United (no codeshares or other complications).

What other bugs are you impacted by? I haven't noticed any with all of the new features and quite regular usage.