I have an iPhone 11 Pro Max. I have tried performing a PRL update (##873283#) and I get the message to start the update but a message that the update is completed is never received. I have tried running the update overnight starting at 9:00pm and checking the phone, untouched, the following 7:00am and no completed message. I have also tried the update on a new iPhone 11 on my account with same results. Please let me know if this is normal or does the update take more that 10 hours.
I have very similar issue. I am unable to update PRL on iPhone 6s with iOS 13.6.1
I am long-time Sprint customer I am having cellular connection issues.
Since merger with T-mobile I thought updating the PRL could help coverage.
I get "Service update failed" message almost immediately.
power cycling / rebooting phone does not help.
Did you find an answer to this issue?