My first question is where in the world you are? - or at least which languages and characters are configured on your devices? Is the Ȁ character part of your regular working character set?
The next question is how you are creating these files (which app? which device?).
Finally, where are you seeing the files stored and listed as your screen shot? Is that on a PC or MacBook?, hard disk? Removable media? Cloud storage?
I can imagine two most likely causes, first that whatever creates these file names has got a corrupted default extension setting. Second would be a character set and regional settings issue or mismatch between different devices. Having said that, I am certainly prepared to find that guess is way wrong