Yealink T46G+T48G with EHS & Jabra Suddenly Switches to "Off Hook", or disconnects

[Complea_KJM]

Hi
We are experiencing some issue at a Customer.
They are using Yealink T46G & T48G with EHS36 and Jabra 920Pro headsets.
When the headset is in the base, suddenly the phone looks like it is "Off Hook", and after a couple of seconds it switch back to idle (We also experience this at our Office with T46G+EhS36+Jabra Pro9470).
Related to this, it sometimes messes up the "Sync" between headset and phone, and the headset base thinks it is off hook, and the phone is on hook. When you then try to answer a call/activate headset, it hangs up, and vice versa.

They are also experiencing calls suddenly getting disconnected. When we run traces on the system, we get a correct "200 BYE" command from the phone, but the user hasn't hung up, making us believe this is related to the headset issues, and the headset ends the call, causing the phone send a "200 BYE".
We have tried switching headset (They used Jabra/GN9330 before), replaced the EHS36, and replaced the Phone. It is happening randomly.

Phones are running latest firmware (xx.83.0.35), EHS36 is firmware 4.16.0.0, and headset are running latest firmware.
Phones is connected to PoE and PBX is 3CX v15.5SP4.

Do you have any suggesitions on hand, or what king of logs do you need to investigate further?