We have an old category it has been disabled for sometime, but there is 28 products in there, see here: https://www.screencast.com/t/mFd3nOPYvi8I
And then here: https://www.screencast.com/t/xbzpqghVS
But when I check 'Reset' all 28 products appear!!
When I check each product in CAtalog/product there they are not selected to be in that category.
This is a mystery to me... how could it be happening? It is like a ghost from previous settings.