EXP39 connected to T46G phone doesn't work correctly

Dear Support Team, I'm already owner of 6 EXP39 and want connect these to a T46G phone.

The EXP39 is detected correctly, LCD is working good, it blink red if an extension ring, or become red if an extension is busy, but it doesn't become Green if an extension is Free, and don't do nothing if I press a button of EXP39 (of course the same exp39 connected to a T28 works like a charm).

There are some known interoperability bugs between T46G and EXP39? Firmware upgrade needed? Any patch available?

I already looked forward for the new EXP40, but my customer want continue to use EXP39 and my reseller right now can't sell me the EXP40.

Best Regards!

---

I discovered a solution about missing Green Led:

Into: Features / General Information
LED Off in Idle: Disabled (Default)

Change to Enabled to make Green Led working.

But if I press the Extension button of exp39, it doesn't make nothing, any suggestions?