iPhone 17 Pro Max cellular service is poor

Question

Level 1

4 points

iPhone 17 Pro Max cellular service is poor

Hi, my iPhone 17 Pro Max’s mobile service is appalling. Everywhere I used to get good service on my iPhone 15 Pro Max is now not enough to even hold a phone call. I’ve spoken to my network provider many times, I’ve reset my iPhone 17 Pro Max, updated IOS. And when I put the sim card back in my iPhone 15 Pro Max, the service is drastically improved and I can hold phone calls whilst driving unlike with my 17PM. Why is the latest flagship model awful at its most basic and primal function? And are there any tips on how

I resolve it?

iPhone 17 Pro Max, iOS 26

Posted on Jun 28, 2026 4:06 PM

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Answer 1

sberman

Level 10

277,796 points

Jun 28, 2026 6:02 PM in response to jdabennett

Here are a few potential remedies:

Toggle Airplane Mode. Turn it on, wait 10 seconds, and turn it off.
Restart the iPhone.
Check for a carrier settings update. Manually update carrier settings on your iPhone or iPad - Apple Support
Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings

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Answer 2

SravanKrA

Level 10

444,858 points

Jul 2, 2026 1:53 AM in response to jdabennett

If your iPhone 17 Pro Max is showing weaker cellular signal compared to your iPhone 15 Pro Max, the issue is unlikely to be with the device itself—unless it has been physically damaged, such as being dropped and affecting the internal radio. To rule out a device fault, try testing with a different SIM card. This will help you determine whether the problem lies with the phone or with your carrier’s connectivity.

Please check the bandwidth that you are getting. Disable WiFi before running this Field Test.

You may check the current LTE band/5G/4G/3G by dialing *3001#12345#* pressing the call button and then selecting the Serving cell info option

Bandwidth on the 2nd and 3rd Screenshots.

See the pic below which is self-explanatory

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Answer 3

jdabennett Author

Level 1

4 points

Aug 20, 2026 10:20 AM in response to MarkoVanCapo

Hi, yes I sold my iPhone 17 Pro Max and bought an iPhone 15 Pro Max - issue resolved. Now I don’t get dropped calls, I don’t loose 4G/5G in low signal areas anymore.

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Answer 4

jdabennett Author

Level 1

4 points

Jul 2, 2026 1:39 AM in response to sberman

I have tried the methods you have asked and it’s still the same, if I drive on the same road as my friend (friend as passenger) who has a 15 pro max on the same network with the same plan - I loose signal everywhere, he does not.

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Answer 5

jdabennett Author

Level 1

4 points

Jul 2, 2026 9:27 AM in response to SravanKrA

Hi, thank you for your detailed response. The signal isn’t necessarily showing a weaker signal, it just doesn’t work in spots where my iphone 15 pro max did. It’s been the same since I had it from brand new out the box, I have tried a different sim card on a different network and it’s equally as bad. I have looked at Field Test and for some reason everywhere I go it’s pretty poor dBm numbers. It’s almost like the newer Qualcomm X80 is worse than the previous X70, or the construction/antenna of the 17PM is worse.

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Answer 6

Aug 18, 2026 6:40 AM in response to jdabennett

Did you ever figure it out? I’m currently experiencing the exact same problem (same device)

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Answer 7

Aug 18, 2026 6:41 AM in response to SravanKrA

When I dial *3001#12345#*, it just comes through as “Error performing request, unknown error”.

Any ideas?

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