GL-Inet MT-1300 White Light but no internet, zerotier bombs out

HAd a GL-Inet 750s, dropped connection on eht0.2 (WAN) every few hours. Changed cables but to no avail. Anyway gave it back and got an MT1300 in the same apartment. Running latest firmware, updated right after unpacking. I am behind a CGNAT. I only have 3 clients on wifi and one wired. I have set up Zerotier for access outside the CGNAT. Only one other package, adblock - standard and LUCI interface for it. Memory sits at around 70% (free or occupied? Can’t tell). It was rock solid for a week, I thought it was all great until one day - no internet and no wifi although White light was on (!). I turned the power on / off. Fixed the Internet and Wifi but still no access through zerotier. The router is present on zerotier (ONLINE) authorised etc but no access is possible. Fiddled with the firewall, all seems to be ok (open port 9993 or whatever). Rebooting it (from SSH) would lead to it blue flashing forever. Strange. So I did a Factory Reset and put back all settings includign downloading ./ installing adblock and zerotier. It all worked great…, had access to interface, SSH, internal storage (using an 128GB SD Card) for a day then again no internet although white light showing. I had enough so i pulled it and put in an old modem. I wonder what (if anything) I am doing wrong. The log showed nothing wrong. Hardware issues? For a second modem in a row?? Any ideas anyone… I really like these routers but they have to also work…

Can you let me know what is the wan connection? pppoe or just dhcp?

When you have no Internet and no wifi, can you still connect using Ethernet and get the log? If yes can I check the log?

At least there is a way to check why there is no Internet.

Sorry in the meantime I sent it back. I had no more time to fiddle with it. It works great for a while and then it stops - maybe because it si more a travel router than 24/7. I’ve put in an old modem / router Billion 7800VDOX whcibh works flawlessly - for now anyway. No CGNAT access but I’m using Zerotier and AnyDesk for now. Maybe in the future these small GL-Inet routers will become suitable for 24/7 operation. Thanks.