m4a audio files

I have been using m4a audio files and they've integrated fine, until today. I was creating a dictation ativity and was not able to upload my files. The error message indicated that those file types were not allowed. Is that a glitch or a permanent change? I use Dictation a lot, but if I can't upload m4a files (the default file type of Voice Memos) I don't know what I'll do.

Bug in Dictation under Chrome on MacOS Mojave

When answering two dictation sentences and evaluating them the first answer gets greyed out. There is no evaluation and you got to reload the page.
Just entering one of the two sentences and evaluating them works though. This happens roughly 2 out of three times.

I only get this behaviour in Google Chrome under MacOS Mojave (both latest version).

Dictation quotation marks

I'm trying to create a dictation exercise, and when the text in the "text that should be written" box starts with a set of quotation marks, something strange happens—on the student's end, even if the student types the entire sentence correctly, it always says that the student has made at least one mistake. When the student clicks "show solution," it shows a blank error box at the very beginning of the sentence, as if the student missed a space before the quotation marks or something.