Ater an update a few months ago, I’ve had Issues with my FP5 and T-Mobile (Germany) as well, but it was definitely the drivers, as it worked before. The chipset suddenly didn’t like the frequencies used by T-Mobile for 5G and lost connection after a few seconds. Fortunately, it was fixed by the next update.
That’s an issue of the particular device, not of /e/OS itself.
First one yes, drivers could be better. The second one I’m blaming on T-Mobile.
Ater an update a few months ago, I’ve had Issues with my FP5 and T-Mobile (Germany) as well, but it was definitely the drivers, as it worked before. The chipset suddenly didn’t like the frequencies used by T-Mobile for 5G and lost connection after a few seconds. Fortunately, it was fixed by the next update.