I just downloaded and patched the game today, and I have a bug to report.
I am Playing on the Delta emulator on mobile, both Game and emulator are on current version. I Chose Turtwig as my starter and I used save states for the resets to get a good IV spread/Nature, I also used fast forward regularly because I'm just too impatient.
When my turtwig first leveled up, the game froze to a black screen when switching back out of the battle screen into the overworld, with distorted sounds to be heard. The bug was reproducable, I couldn't level up or game froze. Also resetting and loading from a normal save game didn't help, as well as not using fast forward mode. Level up -> Freeze. Then I sat the phone down for a few hours, tried again and now everything works just fine, even with fast forward. Maybe it was a Memory issue? 🤷*♂️
I also had a striped screen after the "receiving the poke vial" dialogue, but when leaving the Poke center everything was normal again. I will continue playing now, I love your game and I made an account on this website just to report this bug. Hope you keep up the great work! :)