Cannot connect to webinterface on Openwrt routers

[QuaintGroup]

For travel I have a Slate AX (GL-AXT1800 v4.6.8) router from GL - iNet, this runs a version of Openwrt (Luci v4.4.60).

I have tried a Raspberry Pi 5, windows and mac os version, connected to this router and I can't open the web interface on a other device.

On routers without Openwrt it works fine.

I also tried a other router with Openwrt, same problem.

Control of the equipment works fine. But I only can change setting on the machine running companion.
The Raspberry Pi is running headless so I need to access remotely