This is a normal progression to making money in n/l.

You used to wait for a hand to bet and weren't getting paid off enough to make much money. So smartly, you started betting at pots you didn't hit and were getting folds, ending up in a profit. After a lag period, now they are calling, so now you adjust to that and mostly wait for a hand before betting and now they will pay you off (which they weren't doing before), which will end up in a profit. After a lag period they will probably stop paying you off again and then you start betting at alot of pots again.

This can be done repeatedly against players who pay at least a little attention to you but aren't strong enough to defend well against these methods. Weak players have no defense against this, strong players will find ways to adjust.