In my frustration at this problem not being fixed, I went and created an emulator for the Galaxy A20 to try to pinpoint the problem. The issue seems to be that there is no definition for the Galaxy A20 within Ren'Py, and so it uses the default (size-based) method to determine whether the device is a phone or tablet, which comes up with "tablet" for screens larger than 6 inches. Since Ren'Py doesn't recognize the device as a phone at all, even my workaround here doesn't help.
At this point, I might have to force all Android devices to use the phone layout to make it work on the Galaxy A20 and similar phones. While I consider my options, can you try lowering the screen resolution on your device temporarily and try opening the game with that setting? It managed to trick the emulator into using the layout for phones, but I don't know if it works on real devices.