My husband and I have been living less than a year in a house with 5
bedrooms n 4 bathrooms and every so often a toilet clogs which amazes me
since we're just 2 people and a dog (dog doesn't know how to flush so he
goes in the yard).

We've never had any guest in our house since we moved, we don't flush
anything other than TP and our own bio wastes. There's one bathroom upstairs
that's worst of all and it's in the hallway, not so much problem with the
master though.
My husband and I had a discussion over how to use the toilet paper, he's
accusing me of folding it the wrong way - we buy the fluffy ones, I heard it
can be a problem.

It's a second hand house, there was a family of 5 living here for over 20
years before we moved in.

Am I to blame for folding tp sheet by sheet instead of just crumpling or
ruffling it? - not sure what verb to use here.

Thanks for your concern.