I am honestly at a loss for why it is displaying that way for you and am not familiar with any settings on the teacher side that would cause that. Is anyone else at your school seeing the same thing? If another teacher is seeing something, that could suggest a setting by your institution is the cause.
You are correct that if this appears on different devices, it is more likely not a browser issue. Out of curiosity, did you use the same browser on both devices (Chrome/Firefox/Edge/Safari)? If yes, try a different browser real quick That will likely be a suggestion support would make, so if you can take a screenshot of the issue from two different browsers, that helps rule out possible causes.
At this point, after checking both of the suggestions above, I'd suggest submitting a help ticket. To do that, click on Help on the left side of your screen (in Canvas, not here). Then select Report a Problem. Definitely submit screenshots and include what you have tried so far (between everything discussed on here).
