Updated to v203 on iOS 14 public beta, crashing for me but only after an hour or so of use (I only logged in once with live test code, same as the initial users post). Rebooting device does nothing. This happened only a few minutes a go (as of time of this post).
It also appears though that the live preview on x.thunkable.com freezes my browser tab, though I believe this may be my app. This never happened before though.
(edit)
That second part was all on me. Crashing still persists on iOS but browser is fine.