I have contacted Galaxus Internet Support. Status: 24.11.2025. The answer:
The Zyxel AX7501 itself basically has the bridge mode function, but this is deactivated for technical reasons, i.e. you cannot currently use bridge mode with our fibre router. However, we are working on making this available in the future, but I cannot give you a time frame at the moment. You can find all information and further technical data here.
https://helpcenter.abos.galaxus.ch/hc...