Nano CH340G + SIM7600E-H: LTE insufficient signal despite strong network availability

Code addition is working, thanks. Now look at this interesting output (I only include the output starting with the usual failure): Signal strength is now indicated with -62 dB... and not at all fluctuating. But at the end it is back to -2 dB. Strange. I am not familiar with C-programming, but why is gprs.getSignalQuality used when this is a 4G / LTE module? Or is this just a generic term for wireless signal?
BTW - I am on a fixed power supply for testing, no batteries.