Flows are now starting with all loop and condition actions trees collapsed. How to change this?
Debugging the loops when there's an error, is nearly impossible. Welcome to the #halfbakedpie.
That said, manually restrict your loop to run a single item, just to ensure that it still works. From there, bump it up to 5 or so, and see if it nets an error that can be troubleshot.
Feel free to discuss what's happening inside the loop, as maybe that will reveal the cause.