Should Router losing connection to internet affect wifi speakers and printer?

[#1]

Hi

I am experiencing a lot of problems with my fibre connection.  Even when plugged directly into the test socket, the connection goes down several times an hour. No more watching Netflix in my house. -(

Plusnet have detected a fault on numerous occasions "with the copper wire somewhere between my house and the green box".  However, it appears to be intermittent .  Openreach have been out twice and couldn't find a fault.  They have been called again (3rd time in 3 weeks) and should be here in the next few days.

But I am wondering if it could be the router.  And I wonder if this could be a clue.  I stream music directly from my PC or my phone to my speaker via wifi.  Also, I use a wifi printer.  I wouldn't expect a problem with the line outside of my property to affect the streaming of music on wifi or wireless printing.  Yet when broadband goes down, my music stops and my printer can't be found.  I have a HUB One.

Is it normal for line problems to affect wifi connections in the house (that are not accessing data outside of the house)?

[#2]

Why not try disconnecting the router from the internet by taking out the DSL cable and seeing is you can stream music. It might well be using some on line facility that you're not aware of. If you can stream then leave it on for an hour or two and see if it drops