[Google Pixel 7 Pro] EtherealRemnant:
I had to factory reset today (actually I used the Android Flash Tool just to make sure I had a totally clean slate). I was using my Boost (AT&T) pSIM with my Tello (T-Mobile) eSIM no problem but I installed the eSIM for the free T-Mobile Network Pass yesterday and it was acting weird. Kept losing data, sometimes I would lose both my Tello and T-Mobile eSIMs... It was very strange as I never have any issues with the phone so I swapped the T-Mobile eSIM for my Boost pSIM at which point Boost and Tello started working together perfectly again.

Well today I decided I wanted to see if the T-Mobile eSIM was working any better. I mean it should seeing how my Tello eSIM on the same network works fine. I tapped on the T-Mobile eSIM, it prompted me to turn off my Boost or Tello SIM, I told it to turn off Boost, and immediately I was right back to having data and signal issues. Went to turn my Boost pSIM back on and it was nowhere to be seen in the network settings. The phone acted like there was no SIM at all. Removed it, put it back in, rebooted the phone, reset network settings... Nothing would work. Even worse, when it was in, it knocked out the signal on my two eSIMs right after it got inserted each time. I freaked out thinking my SIM slot died, pulled out the Boost pSIM, stuck my old Tello pSIM in and... It popped right up. Put the Boost pSIM in my OnePlus 9 and it worked there so I knew at this point it was my phone but I thought that it could still be software. Ended up biting the bullet and restoring the stock .031 ROM (I was on the beta 3 QPR), stuck the pSIM in when the phone was at the home screen, and I was back to having both my Tello eSIM and my Boost pSIM again.

I don't know what was up with the T-Mobile eSIM but I removed it since I have no desire to mess around with this and have to reset again. This could have been a fluke or it could be a legit bug. Also, I forgot to mention, I tried disabling the T-Mobile eSIM when I was trying to get the Boost pSIM to be recognized again and the phone said that there was an error. Same when I tried to delete it. I had to reboot to get it to cooperate.

I would advise people wanting to mess with dual eSIM to be careful. This isn't the first glitch I've had with it. In fact the first time I enabled dual eSIM, Settings crashed, and I have gotten the error turning off an eSIM once before as well when I had US Mobile eSIM and Tello eSIM active and wanted to switch back to my SafeLink pSIM but that time it just took a reboot to fix it.

As for the T-Mobile eSIM issue, my guess is the phone didn't like two SIMs connected to the same network. It could be a modem limitation. On my 12 Pro Max I was able to use Tello on pSIM and T-Mobile on eSIM no problem but that could be a Qualcomm vs Samsung thing or it could be specific to dual eSIM. Like I said, I'm not willing to mess with it anymore. I had to do all this at my partner's house and I ended up losing everything on my phone besides what was backed up to the cloud by Google. It's not a huge deal as none of it was all that important but it's a pretty big inconvenience as I had about 50GB of stuff on there that I'll have to manually download and restore.