Issues after reboot?

[TheLastProject]

Google Play Review:

Looks good, it works as expecxted. Needs more testing though. I'd like to have an abiltity to start it on boot automatically, is it possible? Yes, you are right. It just does not work if first call is when screen is not locked. After call with locked screen it always works. Strange, but true. Not a problem at all. Thank you!

Very weird, needs testing to see if it is reproducible.