PS: To clarify, my subscription is with FL1 (FL1 Free! - https://fl1.li/de/mobile-abos/free), which uses the Sunrise network in CH). I have tried using the FL1 APN profile, and tried turning NAT...

Hi, The 4G+ LED on my MR600 v3 regularly switches between on and off. Network Mode is 4G Only. Selected Manual Bands are 3 and 20 (Sunrise - Switzerland). ISP settings shd be correct and current (ISP...