I just submitted one this morning from my phone that said bug reported submitted. I don't remember seeing that before. Let me know if you got it, I may have an idea what's going on if you did. The subject is "test".
Updated
I submitted another bug report when I got home and received the message saying the report was submitted. I didn't receive an acknowledgement email.
Here is a link to the message I received.
https://1drv.ms/u/s!AkQaEoelqApSt1ab...l6ryM?e=hFkfgG
I always send links to screenshots shared on my MS One Drive with bug reports would that be triggering a spam filter possibly?