T41P BLF not working

Hello,

i just bought 2 T41P's but i can't seem to get the BLF leds to get to work
i have a hosted pbx (3 inbound channels, 1 outbound).
currently only those 2 phones are connected (extention 100 and 101)
below the settings


apart from this i also enabled :
features -> call pickup -> visual alert for blf pickup

account settings

(just replace 100 by 101 for the second phone

any other settings that i still need to change to get this to work?
for the moment no lights are lighting up...