I just recently bought this strap and installed it on my Quest 2 earlier today. After putting it on and trying it out, something was immediately off; instead of seeing the passthrough cam and being prompted to confirm the guardian zone, I was greeted with a black screen and an error message saying the device couldn't initiate tracking. After hanging for a few seconds, the error disappeared and things proceeded as normal, tracking and all. I tried restarting and power cycling the Quest a few times to see if this would repeat, and it did in the same manner. This did not happen at all before replacing the strap.
Once in the Home, tracking on the right controller was way off, often being nowhere near my hand and invisible no matter where I looked. After more testing and reboots, it would be perfectly stable until I set the Quest down to enter its low power state; putting it back on would send it on the fritz again. After even more reboots, without changing any settings, tracking seemed to be normal again. I could enter the low power state, leave the room with the headset, and do all sorts of similar things and still have the controller be tracking properly. At the time of writing, it's still behaving as expected. This also did not happen before replacing the strap.
I'm just wondering if I may have damaged something on or in the Quest during the strap installation process. Getting the default elastic strap off was no hassle, but I did have to wrestle the new strap on while still doing my best to be careful. I didn't hear or see anything that would suggest damage had been done. I doubt this would be a software issue given these problems began promptly after installing the new strap. Is there anything I can do to verify if something has gone wrong?
TL;DR After replacing the head strap, I get a "tracking lost" error on startup that goes away a few seconds after, and my right controller was having serious tracking issues that have since resolved themselves. How can I confirm if I have damaged my hardware?
Maybe try going into your Quest setting/guardian and delete its history, then set it up again. I found I needed to do this a couple of updates ago and after resetting guardian all has been fine since. Also, make sure you put in fresh batteries before doing this. Good luck.