iPhone 15 Pro slow 4G internet and data speeds 17.7.2

PS. I checked the internet and it says 17.7.2 brought this modem firmware:

iPhone 15/Plus/Pro/Max: 1.70.02

so clearly there is a major bump for the firmware and so your assumption is very likely to be spot on. Sad though that Apple does its usual tricks of not telling people what they are doing.

yes there was ,but as you can see I have decided to go ahead and upgrade and will test later. Seems the modem firmware is totally different for 17.7.2 ( 1.70.02) and 18.2.1 (2.31.05) for iPhone 15pro

But as 4G is more important to me than some poorly executed Apple core apps, I decided to move on and test with 18.n

I see your point and I agree that the issue could be with a firmware bug (potentially) but could also be with other iOS issues not just firmware.

As it happens, 4G speed is critical for me so I decided to go ahead and upgrade to 18.2.1, I am flashing it now on my Mac so will test afterwards and see how it performs.

Shame I did not capture the modem firmware before I started the update -- it would have been nice to see if they actually updated the firmware!

Thanks Jeff,

actually the devices comparison here is irrelevant -- I provided second device here only as an example of what the actual 4G modem speed is in the location. My own iPhone 15Pro was achieving the same speeds (ca 100 Mbps) before it got updated to 17.7.X

So the issue is entirely with the recent (I cannot say which) release of 17.n.n. But Apple never made a statement saying that "we downgraded iPhone 15 Pro modem performance with 17.n.n and thus it needs to go to 18.n" I hope you understand what I am referring here to.

I understand that 18.2.1 is the latest version, but I had plenty of reasons not to update, such as stability and some tools that have changed and whilst I was eventually going to update to 18.n I was planning to stay on 17. for a bit longer.

I was curious if anyone else noted this and found the solution, as I am clearly not the only person here with other similar reports.