Yealink T46G firmware - auto provisioning

[staffop]

I'm trying to update some Yealink T46G phones via auto provisioning from the 3CX Management console (V12) The default firmware was 28.71.0.224 and I've managed to upload 28.73.0.48 and update the phones successfully. I've tried uploading a newer firmware (28.81.0.20 & 28.81.0.25) but these don't show when trying to auto provision.
What is the latest firmware supported through 3CX V12 ?

 

[3CXusername]

Not v12 but as a frame of reference:

our v14 sp3 latest FW from 3CX is 28.80.0.110
our v15 sp4 latest FW from 3CX is 28.80.0.130