RB912UAG + Huawei MU609

Hello,
The topic has ben beated before, I know, but after trying almost any suggestion found on this forum, I still can’t have LEDs to work correctly.
The 3G connection works fine, and under LTE info I can see the Modem’s received level expressed in dBm, so I assume the data is there to be used.
I set the LEDs for the proper LTE interface one by one, with type as modem signal, threshold from -105 for led1 to -60 for led5.
I get all leds light up all the time, even if signal is below some of the relative threshold.
Any idea or workaround that I can try?

Best Regards.

Giulio