@ezst036 Hmm. I thought we might have the same problem - I'm also using Oneplus N10, and lost SMS receipt, but not sending, upon upgrading to 20.04 OTA 11.
I was excited to try the two terminal commands you referenced, but still can' receive SMS, so maybe we have different problems? Did yours stop working after upgrading to OTA-11? Do you ever get a strange glitch where upon receipt of a notification, the phone freezes and the phone screen starts rapidly flashing, and won't power off? If not I'll go back to assuming my problem is unique and my particular OP N10 is just cursed
(Also, I always have had the odd MMS that just wasn't received, though mostly they work for me.. often the right APN setting is the trick if they aren't working at all, maybe two different APNs, one for Internet, one for MMS. Sometimes MMS used to break in a way that a reboot didn't fix, but systemctl --user restart nuntium would. But I'm pretty confident MMS issues are totally separate from SMS issues.)