Well if it had updated correctly previously, your reserve file had already been restored, so there was no need to restore it again.
But regardless, all of those errors that were seen if reserve hadn't been restored, or if boot or recovery images hadn't been restored to stock, were installation errors. The OTA was found, downloaded, but there was an issue on installation.
The problem now is that no OTA is being found. I'm beginning to think they possibly pulled 10.0.36 due to some bug, because no one has had to wait for an OTA this long previously. The only thing that should stop an OTA from being seen/found is if one had updated their fingerprint (to spoof a pixel for example).
At least from your screenshots, you see that Google was able to install their "project mainline" update. It's in the pics from security under Google Play System Update (is completely separate from Play Services) dated July 1, 2020.
Let's hope T-Mobile gets this missing OTA crap fixed asap
Yours shows you have a new security update, you said after you msm restored you received the update after 2 weeks. Wonder why mine is not updating. I do use a fingerprint in Magisk to pass safetynet with edxposed, going to try to disable that and see if it has any effect. I do think it is possible maybe they pulled the OTA considering they may have bugs or a newer update is close to coming out(idk). I'll tinker around a bit more see if I can uncover anything.