Not sure if this is the right sub to post this in, but does anyone here have experience with Adva fibre switches?

We've had Openreach (BT in the UK) rock up and install a fibre line that terminates in a adva fsp150cp fibre access switch, which apparently is one built specifically for Openreach so I'm struggling to get a manual for it.

It looks like we've got the option to use either ethernet or fibre to go from this to our router, but according to our provider only the fibre will work "because the connection is too fast" for ethernet. This is only a 100mb line and lets just say the provider hasn't been 100% accurate with their advice so far.

Anyone here run into this kit before and if so did you get it running using ethernet?

edit: It's one of these - https://www.itinstock.com/adva-fsp150cp-optical-fibre-access-switch-f150bt-cpgig2ac-0078993005-42179-p.asp - nice to see British Telecom sparing no expense :)