@yrannadx

This message needs a huge sleep (for getiing the network code reliable). So I added a 30 s wait. Seems not to be enough in all situations. Especially not using param iap and forw_aft. So I added a infinite loop (no messages/popups) just before that to assure SIM is online before getting/printing network codes.

For your special problem I tried to switch forth and back with an sleepy/idle device and I could not reproduce. So I have no chance to support you here. The only way to get device into "app icon state" would be to unlock, which is not a good idea.
At first I thought it could be some lagging or swapping problem, but I tried with no delay between call and call release and no prob. So I am running out of ideas. Maybe try to do some research with longer sleeping time between call and call release, or add sleep time between call release and phonet down or add a second call/call release or or ...
Or it just may be a flaw of your adapter (like mine has when giving code2 on SIM2 it switches to SIM1). I am sorry to be not more helpful here. But please keep me informed or ask for more support.

--
just queued 0.5.8 to devel
and 0.5.9 (still learning about packaging on device)