This is really not nice ans still no official posting from 3CX 
!
Where is your
customer support... 3CX?
The only answers I read from 3CX are non-relevant and didn't in any way help to solve this problem.
And I refuse to pay 75 EUR to open a support ticket. I have known the situation in the beginning when support was free for ALL partners, even affiliate ones.
I also have enough experience with support to know how this will work out. You need to do a wireshark trace etc., all not relevant to this issues. The issue is the 3CX Windows client. Not the network, the computer, or whatever.
I've spent hours in the past with support solving problems and reporting bugs. Only when the issue gets high enough in the support chain of 3CX, something seems to happens when it's about bugs.
That's my personal experience, and I don't say that's everyone's experience.
I recall the Fanvill C600 issues, of which I posted about in this forum.
That one has cost me a lot of money, and at that point I really thought about to stop with installing 3CX. But they have some features nobody else has. And for small companies, it's a free and easy manageable solution if you just need a basic PBX without much integration or queues and a decent softphone.
It's hard to believe only the people posting here are having this issue or have customers using TAPI.
IMO 3CX is well aware of the issue, but for one reason or another does not want to acknowledge it, let alone solve it.
I also wonder how much they are still interested in TAPI support, since the last version of the driver is already several years old. To me, it feels they want everybody on the webclient. Much easier to maintain of course then a separate Windows program.
I really don't understand partners have to post here (GaSo is Silver partner, so has free access to support) to bring this to the attention of 3CX and get something done about it.
Just my 2 cents...