Tried several times over the last few days and it finally worked this afternoon.
Sometimes at home it is in WiFi mode and sometimes it isn't...
Not sure if I've talked to anyone with it yet.
Gary
I'm wondering if that is because it goes into wifi calling mode when the signal is weak. Maybe your signal is sometimes good and sometimes not?
Well in my experience WiFi signal can fluctuate or your WiFi router or ISP can have intermittent issues without you being aware so that's not entirely impossible
Why exactly is ATT not supporting this on an iPhone 5s? I think this is really a dis-service to the people who purchased these models knowing they had the capability per Apple
https://support.apple.com/en-us/HT203032
iPhone 5c and later are capable of Wi-Fi Calling. Check with your carrier on which models are supported.
This may be a deciding factor for me on switching carriers. ATT always seems late to the party.
The manner in which they have WiFi calling set up is different from the 2 other methods/means set up among cell providers
In short the 5S/5C came out too soon to have ideal compatibility.
Even if AT&T were to retroactively find a way for the 5S/5C to work the performance of a 5S using WiFi on ATT would be significantly degraded vs 6 6P 6S 6SP and 5S/5C because they also don't have full HD Voice and VoLTE compatility ( key things that make WiFi Calling work it's best ) not only would 5C/5S customers be peeved at poor call quality or inability to make calls but the number of call drops would soar dramatically because handoff/handover
( made possible by HD Voice or VoLTE coverage ) wouldn't be able to properly occur on your 5C/5S
if say your router/WiFi connection craps out, your ISP has a sudden issue/outage, power outage where you are , you travel outside WiFi range, your cell/network/phone signal somehow briefly becomes stronger than your WiFi signal then boom no handover call drops people moan "Oh ATT is the worst this feature was supposed to make the network coverage better not worse"
In short support for ATT WFC on 5C/5S would be difficult if not near impossible , would be a PR Nightmare and a greater customer disservice than simply saying "yeah we can't/don't/won't support WFC on 5C/5S"
And granted while "late to the party" ATT tries to do things right not rushed/half cocked, and they did this legally unlike some carriers lastly Verizon and some others STILL Don't offer WFC so ATT isn't last on this one
Also not to make assumptions cause I know some can't or won't for various reasons but
5C/5S owners are about due for upgrades if not to 6S 6SP then 7 and 7P next year
Also it was ( rightly) assumed/expected by both ATT and Apple that 3GS 4 4S 5 and many 5C 5S customers would upgrade even if they just go to the 6 or 6P