I was unable to replace the 12m run of phone cable, as it goes through a flat roof from modem to my system. I would have done this if possible.
The cable was Cat5, so compatible. My electrician did the work. I’m sure there are videos on how to do this if you are so inclined.
Have read in a few places that your best ethernet cable should be the last in the chain to your streamer, which is what I’ve done. On the modem side I have Meicord Opal, Blue Jeans and Supra Cat8 ethernet cables.
I’m going to keep out of the argument with F2. If ignored, he might stop.