TLDR: I feel like I wasted a day of my life over the Hue terms and conditions change, and am not convinced that the terms & conditions change panic was worth my time (...and I still "lost", as I gave in to it). Perhaps you can commiserate with my frustration, or if you're feeling charitable, tell me what I'm doing wrong.
Long story: Like many of you, I own & operate about a dozen Hue light bulbs, and for many years. Unlike many of you, I am completely new to home assistant; I've never used it before. But, reading about the terms & conditions change for Philips Hue, I bought into the hyperbole, and decided I would do something about it.
I bought a Sonoff "P" zigbee dongle, and plugged it into my Unraid server. I set up Home Assistant (first in Docker, then in VM). I tried zigbee2mqtt and/or ZHA back-and-forth several times.
This stuff is NOT user-friendly. Home Assistant wasn't a terrible experience; it is confusing, but it found & behaved well with most of the stuff in my house... except for those damn light bulbs. Perhaps I'm merely mediocre for this community, but I am easily the most technically savvy person I know in real life, and this was an exercise in frustration just for a dozen light bulbs.
Neither z2m nor zha was ever as good as the Philips hub. Maybe it was my dongle, or the extension cable, or a myriad of other variables I never had to consider with the Philips hub. ZHA was much easier to setup, but it was SLOW, requiring 4 full seconds to change a bulb 10 feet away, and that was when it worked. z2m never found all my bulbs, though its setup was so user-unfriendly it's possible I was doing something wrong. I don't think I ever got either system fully set up how I wanted it to be, and I just gave up after hours and hours of frustration. Because my wife expects this stuff to "just work," I reluctantly went back to the Hue hub and... I had everything reconnected and restored in under an hour. And then, I laughed till I cried--setting up the Philips Hub in home assistant took 10 seconds.
There's probably a better community than this for my frustration--as it's not with HA but rather the light bulbs--but perhaps this community can tell me what I'm doing wrong. The idea of a fancy dongle to control my light bulbs without giving in to "the man" is still tempting, but it really needs to just work.
I found when changing the Zigbee channel with Z2M that I needed to reflash the firmware on the Sonoff Zigbee 3.0 P dongle to erase its list of device addresses, then delete the coordinator_backup.json so that the list of device addresses is not reimported, and then start pairing my devices from scratch.
Z2M was automatically selecting channel 11 which in my case is the same as Wi-Fi access point nearby which was causing interference leading to significant delays or losses in signals (as well as Wi-Fi performance issues on the 2.4GHz SSID), which seems similar to your issue
You are very correct that it is user-unfriendly, but I haven’t tried with Hue products (I find that IKEA Tradfri bulbs work well with Z2M though)
Oh my! That's the one thing I didn't seriously try: flashing new firmware on the Sonoff dongle. I briefly looked into it, but I was having so much other trouble by that point it seemed futile.
That you seriously needed to perform this step is just awful. I'm so sorry!