When did they start hating Catholics?
Never have - there was in 1307 on Friday the 13th when the king of France and the pope attacked the order trying to destroy them. It is Catholics that tend not to accept masons.
There is no rule a Catholic can join and be a mason however some Churches and a lot of European countries bann them.
Germany as an example.
More masons were killed as a percentage of population by the nazi’s the jews.