Remove the *80 from Feature Dial Services and add *80xxx to the phone’s Dial Plan.
For example, change (*xx|[3469]11|0|00|[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.)
to (*xx|*80xxx|[3469]11|0|00|[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.)
That has worked for extensions, but not my Page Group. With that, I just get “Busy”. The only thing that jumps out from the logs is:
“[2018-07-30 16:17:50] WARNING[21463][C-000004f5] channel.c: Prodding channel ‘SIP/101-00000dd6’ failed”
Sorry, I’ve never used that kind of paging and know little about it. However, I believe that the ‘intercom’ function is handled by the page module automatically, e.g. you would dial 500, not *80500. If that doesn’t work, I hope that another member here will help.