My log is filled with Log filled with this kind of thing:
"[2019-08-31 16:46:16] NOTICE[4855] res_pjsip_exten_state.c: Endpoint '24' state subscription failed: Extension '02233936622' does not exist in context 'from-internal' or has no associated hint
02233936622 is a number in my Digium Phones Phonebook, there are other examples for other external numbers, but “subscribe” is not ‘ticked’ - so am surprised a subscription attempt is being made.
The phone/endpoint will only try to subscribe to something if it’s told to. Which is sounding like someone has a BLF setup for this to just speed dial. BLF causes subscriptions.