How would I go about changing the number of rings before voicemail picks up ?
Phones are Samsung Note 5 and Samsung Note 9 if that makes a difference.
The phones used can make a difference.
For a phone ligne WITHOUT VoLTE (voice over LTE), the option to increase the number of rings is the following
PS : simply punch this in your phones dialer.
The number of secondes have to be between 5 and 30, by increments of 5. (so 5, 10, 15 etc)
If the line DOES HAVE VoLTE (the note 9 most likely has it), then the rings is fixed to 20 seconds, can't be modified.