I'm not an expert on Orbot but in which case and how could an IP leak using Orbot, assuming Orbot routs all the activated app's communication only over TOR? And how can an app developer fix this reliably? And how can the user know the client dev fixed it reliably 100% all the time with every update?

I'm talking out of the experience where an app used an installed Orbot to talk to some servers then a new dev team introduced other servers but did not care about using Orbot when the still available TOR option was activated, misleading the user to assume to be private where they are not.