Please upload a small project with the font.
Hello Erel. Here attached is the .zip project.
I have found the problem:
Devices running Android 10+ show only unicode characters.
Devices running Android 8- show both unicode characters and graphic characters.
Using a font editor I generated a new font file adding the unicode characters and they display just fine.
Original file:
New file with unicode chars:
The following image shows 4 devices: the characters on top are drawn using the original font, and the characters below are drawn using the font with unicode characters.
Devices from left to right: Android 12, Android 10, Android 8.1 and Android 7.
Thanks in advance.