Will an update fix signal issues for XS and XS Max?

Yes. You can read about this here:

Writing for the blog WiWavelenght, radio expert Andrew J Shepherd says that he knew this was going to be a problem when he first reported on the lab test data found in FCC authorization filings for the XS and XS Max: “[the tests] raised potential red flags regarding the new iPhones' RF reception and transmission abilities in low signal strength conditions.”

iPhone XS Antennagate Can’t Be Fixed with Software, Expert Says

and here:

https://www.wiwavelength.com/2018/09/iphone-xs-and-xs-max-mostly-fail-to.html?_g a=2.62478635.685668143.1539436494-211162…

maybe the wi-fi problem is now fixed with iOS 12.0.1 .. but the LTE signal and speed no. I dont wanna spend 1200$ and find problems with that.. happy with my X silver, 2 years more with him i hope. But i have to say i buy and try the Xs, and the data speed was low, lowest even compared with my Galaxy A8 2018 and OnePlus 3T.

Your love affair with Apple is undying. Even when presented with FCC Test results you still can't admit there is a problem. The blogger did not do the testing he is merely pointing out that the FCC filings show there is an issues with the new 4x4 MIMO setup. He clearly states it is not the Intel chip causing the problem but rather the actual antenna setup. Get over yourself already. At 1,800.00 with taxes this is a lot of money to spend to be a beta tester. Apple dropped the ball big time.

I said I don't doubt people are having issues. I'm not. I know many other's with XS or XS Max who aren't either. They're on AT&T. I do know some on Verizon, who are having issues. This leads to be confident this is a carrier and Apple issue, which can be resolved with an update. Nothing contained in the blog posts says the results can't be altered with cellular updates. ***
[Edited by Host]

I haven't bashed anyone. I have as much right to post here as you do. I am admittedly on a lot of threads. How else could I have earned over 20,000 points if not by helping people? If simply saying we need to wait for an update is bashing, then you please provide the solution to people who are experiencing this issue. There are three choices people have. Return the phone for refund. Return the phone for replacement. Wait for an update. Do you have a better solution? You are absolutely correct however. I am not an engineer. I've just rarely seen an issue Apple couldn't ultimately fix with a software update.

Have a swell day!

The thing everyone needs to remember is the iPhone is not going away. But your window for returning it is closing. If this is an issue that can be resolved with a software fix than great. Once you know for a fact the phone is working great go buy it. But why let Apple hang onto your money when nobody know what, if or when a solution will be in place. Apple can always create a patch that will show more signal bars but not actually fix the problem. I'd rather hang onto my money, or buy a different phone. Pixel 3 is a very interesting option with all the enhanced AI Android Pie has to offer.

I’m not sure if intel did the Bluetooth as well. I have one more payment on my phone before upgrading to the Xs but I had went into and AT&T store and compared the rsp0 signal strength on their demo devices of the Xs compared to the X and the signal strength was exactly the same if not better at times so it seems to be a hit or miss but hopefully the 12.1 patch will solve the issue for anyone having problems.

LTE:

I don't have issue

Wifi:

poor signal on XS / XS max

no issues with iphone 7 / 7+ / ipad pro / ipad air / MBPs

I did some measurements at the same place in my house where i normally have max bars.

It's a bit a shame that a cheap china smartphone has better wifi reception that this "high end" device.

I just want to chime in here for a second because I feel like that signal strength answer that was given to you wasn’t really a great answer if you’re actually trying to understand. The bars absolutely do show signal strength! That’s what the RSSI information is (the -114 or -80 sorts of numbers you see posted around). This is information is also inversely proportionate to distance. This is due to a law in physics known as the inverse square law and it applies to any and all signals. The law states the signal power or strength is inversely proportionate to the square of the distance the signal travels. So yes, it does show distance in s round about sort of way, but the actual numbers you see, the RSSI info, that’s a signal strength number, not s number directly representing distance. Just wanted to clear that up for everyone.

Ive had the same issues and have posted on here 3 days ago. Apple Care Outreach reached out to me on my cell and I am providing them with data logs of connection issues. So they are working on it!

Note Apple released iOS 12.0.1 a few hours ago now:

I dont now, but today i return my xs.. lte was low and lot of times its looking for signal.. best thing is wait 1 month and see what apple does.. Right now, no recomend buy.

I do not have any signal level issues with my XS Max, but my download speeds are nowhere near what they should be.

My iPhone X running iOS 11 regularly showed download speeds of over 350 Mbps down via WiFi over my 1G Internet connection.

My iPhone XS Max is showing:

The thing is, it doesn't feel that slow in operation, so I wonder if it's an issue with the speed test apps available.

I have a cable modem and upload should never be higher than download (my service is 1 Gbps down, 40 Mbps up.)