T28 BLF park not working correctly

[ziggy5376]

Hi

We are using T28s with a hosted 3CX PBX solution.
We are having a problem where the BLFs we have set for parking are not accurate,
for example, when a call comes in and you park the call, the button turns red and will show red on all phones in the office(which is correct), when the call is picked up by a user the light will remain red instead of turning green as it should as the call is no longer parked . to change the park light back to green you have to press the key a second time and then hangup.
What we also found was the lights were not consistent across all phone in the office, eg. DSS key 1 could be red on some phones yet green on others.
Users are complaining that they do not really know weather the parking slot is free or not
Parking the call looks to be fine(the light always goes red) the issue looks to be when the call is picked up

We went back to our PBX provider and they were not particularly helpful they just blamed it on a internal network issue.
So i connected three phones to an internet line not connect to our network and carried out tests. the results were the sames as what we were seeing on our network, i did the same test on another internet line from another provider just in case, and it too had the same results.
So it leads me to thinks that there is something else causing this other than an internal network issue

What i also found was that if i picked up the the parked call using the 3cx softphone instead of the yealink it worked the lights would revert back to green on all phones,

Any help on this would be greatly appreciated

Thanks