My wife's iphone 14( ios version 18.2, t-mobile cell service) recently stopped being able to make wifi calls at home on the where a GL-SFT1200 router is connected to a Motorola cable modem (Cox is provider).
I believe the loss of wifi calling is connected to my upgrading the firmware of the router GL-SFT1200 to version 4.3.21. The most recent version I have found to work is 4.3.7.
Is / Are there any settings on the router I should confirm / change that can enable her phone to work on wifi with the latest version? Do note that I have an Android phone (Pixel 6a) and it works fine.