Yealink T46G/S power saving mode on 66.82.0.20 firmware

[kristof.daylesford]

Hi,
My phones are T46G and T46S
Firmware Version 66.82.0.20
Hardware Version 66.0.0.128.0.0.0
The power saving mode is disabled by template setting
features.power_saving.enable = 0
and it works BUT after the phone is rebooted it goes to power save mode after 30 mins (i think it's the default value), screen goes black. BTW I managed to switch off the infamous power LED blink on power save.
When the display is waken up from power save by pressing any button, the phone never goes to power save again (expected)
So, only that initial restart puts phone in power saving mode.
Is it a bug? expected behaviour? anyone knows?
it wasn't like that in v81 firmware. Only appeared in v82
Please help