That's weird.  Like I said my install was going strong for a solid 12 months.  My Father has an identical system that I installed back in December of 2020.  He had his house pre-wired while it was being built, that's the only difference.  However the installers didn't use CAT6.  They used 
CAT5 probably, from what I remember.  Smaller diameter wire and no solid core copper.  He hasn't had one failure while whole time.  And I crimped all of his connections by hand WITHOUT having any sort of continuity tester at the time, and got everything working the very first try.  Not bad for a first timer.  The success of his system is what led me to procure the same exact model everything in 2021.