WiFi problems are gone for me totally with the 12.01 update.
So here's my short report after a visit to the Genius Bar. I went in to get my XS Max replaced because of the connectivity issues (wasn't 100% happy with the screen either). They replaced it without a problem (much happier with the new screen) but they told me not to expect a fix for the connectivity issues in hardware and instead it would most likely be a software update. The Apple techs in the back told my Genius that they are collecting information (and asked for my permission to use my phone and call with questions) about this issue and working with carriers to fully support the new antenna system on the XS. So at least part of their story is that this is a matter of compatibility of the new antenna bands with carrier towers, etc. I'm not sure if that's true or not, but it certainly could be. Hope to see some improvements sooner rather than later.
Not necessarily odd, perhaps unusual. I’ve been working to try to narrow down bands, signal strengths, specific towers and more for a while. Some observations I’ve had are below. I’m making no conclusions yet.
I am in a rural area that has towers from my provider spanning two markets. As such, those in my west side are handled by workers in one geographical are while those to the east have another. This is important because sometimes when markets conduct upgrades or maintenance, one will star and even finish before the other even begins.
When I got the XS Max on release day I noticed absolutely ****** LTE. I had a 7 and a 6s with me at the time. Both of those were killing the XS in speeds and signal on a drive I make frequently. As I’m rural I know where the dead spots are so even with that in mind it was bad.
This weekend and today I’ve noticed that the phone is equal to the others in speeds now when making the same trip. (Thanks to my husband for putting up with my mobile lab and driving me back and forth!) There were two small discrepancies that occurred on a single tower in one area. I’ll figure that out soon.
Now, going east I have fantastic signal on the XSM until I get to a location where I had bad signal inside. No data, failures and so on. The other phones were fine. Then, an oddity. All the phones had full signal indoors and absolutely no data. So that problematic tower seems to be undergoing maintenance or failure of some sort.
I’ll update more as I have anything to add; but, the point here is that I think there is some provided tweaking that needs to be done. Perhaps these phones aren’t in the system as they should be. That would help explain why I had early failure in one direction (market) and not the other and how I can identify specific towers with weirdness now.