I saw a comment on this Reddit and I cannot find it It was someone advising about staying clear of CCA as a data cable.
Had been having massive spikes , speed and drop issues.
I replaced my main fiber to router about three months ago to better hide the cable. It was a 48 metre run. When I saw the comment I checked the order I placed and of course the cable product code had a CCA in the middle. Replaced it today with a solid core and the difference is night and day. 150 to 490 mb down and 10 to 90 upload
TLDR: Fuck people that sell or categorize copper coated aluminium as CAT 6 cable.