No incoming call detected when starting MM while an incoming call is already "ringing"

When the modem is being called while ModemManager is stopped (so the call is "ringing" on the other side already), and ModemManager is started in that state, it doesn't detect an incoming call. Only if the incoming call is placed after ModemManager is connected first.

Is this intentional? Is there any reason why an incoming call shouldn't work while starting? If it's not a logical thing that can be fixed, I can provide some logs later.

thanks a lot