Issue with Advance Panel

Hi Chaps

I am service and install engineer with limited commissioning experiance went to do fault finding on 4 loops Advanced panel with loop powered sounders.

Fualt is :

Call point number 27 in zone 7 part of loop 1 activate the fire alarm panel when triged but dont ACTIVATE THE SOUNDERS.
Other devices on same loop different Zones activate the sounders

I tryed the following steps but no joy so Far:

Auto learned the loop and tested call point still works activate the alarm on panel without seting the sounders on.

Changed the Zone number to 20 which spare ,.

Changed the device number into 100 and put it on original zone 7 on auto learned it again tested call point and same activate the panel but sounders didnt work .

Kept call point in number 100 changed the zone to 20 again and tested
same activate the panel but sounders didnt work .

I put the call point instead of existing one one loop 2 it did work and activate the sounders ,

it taken me about 1 hr to do the above and had to leave site cause its home time for care taker I may get back there tomorow to fiddle with it again any Tips apreciated

Please note I dont have software for this panel

Cheers