internet connection- possible PUP causing problems

I started a new cox account at a new address in March.  After a month or so my mac laptop  stopped connecting to the internet. First it wouldn't work with wireless, then not  wired connection either.

Now my PC work laptop won't connect wirelessly.

My desk top stopped working wirelessly- I bought a TP link doggle and it worked for a couple weeks then it also quit working wirelessly.  I am wired in for connection.  When I look up my home connection through Cox it gave me an  " error "invalid device 100DF/100DFF2254B8"  Is it possible that someone in my household is blocking my computers from my home network and how do I stop it?

I had these same EXACT issues at my old house.  I was looking forward to having internet here.  I am the account holder.  No one else in the family has the problem.

Please, PLEASE HELP ME.