I just today started having an issue wherein the messages I send to a group chat via MMS from the Windows 10 app will sit with a "sending..." message in the Win app, then disappear from Windows 10 and not show up in my Android (Pixel 3) messaging app (stock/Android), but the people in the Group chat still got and saw them. I ended up sending the same message 3 times to a chat because I didn't think it was sending, only it was and I wasn't seeing it.

This only occurs on MMS messages. SMS works as expected.

This was working fine in the exact same group chat last night, just started today. It's very frustrating, because I can't tell what I've sent on either device!

I checked to make sure both apps (Win Android) are up to date and tried again, no luck on fixing it. Anyone else having this issue? Any ideas on how to fix or is the MMS group chat support just buggy?