@Sunshine provider is Drei (hutchinson Austria). I am not on site so this will be sorted now with reboot only. then I can share FW version with you. This was happening with ZTE router but not that...

Hello, I am having TP-Link Mobiler AC1200-Dualband WLAN 4G+ as an Access point. Using LTE network. It disconnects from the world at least one per month and is then also no accessible via app...