Cannot upload a 4.73 MB video: Told it's over 10 MB

I’m on a brand-new devsupport account and trying to upload a short video (4.73 MB) to illustrate my problem. The forums are giving me an error:

Sorry, that file is too big (maximum size is 10 MB). Why not upload your large file to a cloud sharing service, then paste the link?

I’ve moderated Discourse forums in the past, and the video was going into my very first post in the forums, so I know that I’m probably being blocked right now because I’m at Trust Level 1 and there is probably a restriction there. However, if that’s the case, the error message is misleading.

I’m aware that I could upload a file somewhere else and link to that (although, I’m not so sure if I’d even be able to do that at TL1): I’m posting this simply to point out the error message doesn’t make sense.