Even with the mentions of Coinomi developers incompetence it is a widely used wallet. For some reason or other I never used it, I think I might have downloaded it around the time I started this thread but I was never very comfortable with it but I could never put my finger on it, I would cite it as a gut feeling. I do think that with other options out there your advice about not using Coinomi after his issue is resolved is correct, if someone had a bad experience with a wallet then better to move on but only with caution and after carrying out lots of research.
I bought some USDC and sent them to my Coinomi wallet, but they have never appear on the wallet. I have no way to use them, despite I can still see them on the Etherscan.
Coinomi has quite a few problems. And one of them is the fact that the developers are pretty incompetent.
I hope you can fix your issue somehow. It might be just a connection error, can you confirm that you actually have an active connection and the up-to-date version?
After you gained access, you might want to user a proper open-source wallet, and not a wallet whose developer think its not a severe vulnerability to spell-check your mnemonic code with the use of google.
I'd definitely suggest you to not use coinomi after fixing your issue.