Single App Mode breaking CallKit

[scarey]

Hi everyone,

We just built a new FreePBX phone system and have a few iPhones for the staff that aren't tied to an office desk. These phones are just for the new phone system so we want the SIP app locked. We have trialled several SIP client apps and they work great until you place the app into Singe App Mode. Once in Single App Mode, incoming calls no longer show the incoming phone call screen and instead show a small, non-interactive banner at the top (see photo below). There is no way to answer a call and the banner disappears after a few seconds.

As soon as the app is removed from Single App Mode calls come through fine. This is the same with every SIP app we tried; they all display this non-interactive banner when in Single App Mode and work fine when not locked.

Does anyone know if this is a known issue with iOS and if there is a fix coming? Does anyone know any workarounds?

[mainelysteve]

@scarey I'm assuming you are getting these into single app mode via a configuration profile? Have you tried doing this (Settings > Accessibility > Guided Access) on the device itself to see if you can replicate the issue? I've had wonky things happen with sam that was triggered by a config profile.

[scarey]

Thanks @mainelysteve but the issue occurs when using Guided Access too. We tried a number of different VoIP apps and one suggested that Do Not Disturb was enabled when we tried to make a test call. It wasn't enabled before pushing out the config profile or setting Guided Access so maybe SAM puts CallKit into DND. Can't see a way to override this behaviour.

[mainelysteve]

You could lean into that and proactively enable DND then set exceptions for all calls to come through. Although I'm not seeing DND behavior mentioned in any single app mode literature, anywhere so I'm at a loss. It's worth a shot though.

My last resort would be to send out a home screen layout config profile to make the voip appear on the dock. You can then hide the rest of the apps using a restrictions profile. Not ideal but it would cement the idea into the users(and the people upstairs) brains that the phone is for voip usage only.

[scarey]

Thanks @mainelysteve, good call because that is currently what we are doing. We have all apps hidden except the VOIP and Settings (can't hide settings) apps. Problem is, the users close the app despite us stressing it needs to stay open! Trying to make it a foolproof as possible but guess we will have to leave as is for now. Thanks again