BLF vs Extension on Snom Function Keys

[ps1]

Hi, sorry formmy english, I try to explain my problem as best as I can

we migrated a host from a very old fusionpbx (4 I guess, debian buster) to a current version 5 and debian bookworm

we have snom phones with "extensions" programmed to function keys.

before migration: button light green when ext ist called or ext is busy. hitting button can get unanswered calls.

since migration the lights go up/down randomly without any order.

when set the function key to BLF the messages are acurate (but then the funcionality tomget the call is missing)

any idea/help?

 

[ps1]

ok, after some testing we see, that BLF doest work either reliable. its up/down randomly.
now testet on to different systems (customer and lab), different networks.

any idea?