the main issue working with mangOH red and the WP77 is mangOH red is not able to supply correctly the WP77 because mangOH red uses the power supply from the USB (even USB 3.0).
My Sierra Contact recommended me power the mangOH red with an external power supply and now works perfectly!
I suppose mangOH green doesn´t have this problem because is powered from other than USB.
Please, if you are using WP77 and mangOH red take this into account.
That might be due to inability of USB power supply on your computer to provide the necessary burst current. So yes in that case use a USB connected wall adapter.
Power supply requirements (current and rise time) for GSM are significantly different for GSM and LTE.
Table 3.3 in the WP77 PTS indicates that typical supply current for LTE is 800mA and for GSM is 1.0A, and the Max current for LTE is 1.5A and for GSM is 3.0A
I have also had modules ‘black-banned’ from the network because they were not meeting transmission standards - in my case it was always an issue with the power supply not being able to meet the TX specs.