I would try from Attendant handset (Station 100 usually, find it by dialling 9 or 0, whichever doesn't seize CO Line) and dial in TRANS / PGM 0 2 2, and enter station range 109-109, then Hold/Save.
Check auth codes in LDK programming PGM 227, Authorization code table, refer index number to the the jack station 109 belongs to (should be jack 10/ Index 10. Check this in Numbering plan). If an authorization code has been entered previously from that station, it will appear in that chart.
If you have a VMIB card installed in your system, press Trans/PGM 64 and listen to the station status. Listen for word "Locked" Locked means COS Down as activated at this station. "Class of Service : x " will play after all other status' are read out. If the Class of Service is not 1, or matching another station, you should change the COS by using PGM 116.
Hope this helps you!
2311angel