Are you trying to format the text using manually entered markdown symbols (for example, two asterisks before and after the text for Bold), or trying to use the markdown ribbon tools shown below the comment box)?
I am not able to apply any of the formatting from the markdown ribbon tools, no matter what font size I select.
I could manually do it with no problem. But the toolbar wouldn't work because my text was set to Larger. I'm on android 13, I'm not sure if the problem is device specific.