Hello, if you consult the Digitec product sheet, you'll see that this question has already been asked by a user. The answer is that this box works perfectly with Sunrise. The person who replied even explained in detail the settings to be made.

yes, it works, even flawlessly ;)

just needs to be set up correctly, so:
there are several things to consider, speaking from experience, all options work

1. possibility
- connect
- log in
- it works

2. possibility
- connect
- log in
- internet
- access data
- internet provider sunrise
- access type sunrise fibre l3
- now running

3rd possibility (if
way 1. & 2. does not work)
- disconnect pc/laptop from the network
- connect fritzbox to pc via lan
- log in
- system
- backup
- factory settings
- load factory settings
- disconnect fritzbox from pc
- connect
- do 1st or 2nd option
- be happy