Isolator cable

Hi,

I have just left VM and am returning the Wifi Hub. When VM was installed in 2020, the installer rather than putting a faceplate on the wall installed a white plastic isolator cable directly attached to the end of the black external cable coming from the brown box outside. Not clear why they did it this way rather than a faceplate but I didn't challenge it at the time (usual practice?).

The isolation switch is then connected to a short white Type F cable, then to an 8db Forward Path Equaliser into a 2 way splitter which was connected to TV/Broadband.

This has left a mess of cables that are no longer needed and I want to keep the bare minimum of cables attached but still allow for later self-installation if required.

It seems the sensible point to put the silver terminator cap is just after the isolation cable. However, although it looks to be a screw on type F connector, trying to use the spanner to remove it also spins whatever is inside under the white plastic meaning it won't come undone. Should I be able to remove this cable, or is something broken in it allowing it to freespin? Short of removing the white plastic casing and to get a grip on it, i'm not sure how to get this cable off.

The only alternative means needing to keep everything attached up to the splitter (messy cables), and they only provided 1x termination cap (so only 1 of the ports would be terminated).

Picture attached.

Thanks