Hello,
I would like to know if this cable is compatible with the Swisscom Internet-Box plus
Thank you in advance for your answer

You can fix them with adhesive tape on parquet under a carpet or with the small clamps from Migroh for two-core telephone wires that I still had lying around in bulk.

in my case, the new fibre optic socket was also installed in the wrong place. and this cable worked great, just be careful not to bend the fibre optic cable too tightly... if you want to tighten it on the walls/floor, take note of this!