You have discovered a mysterious effect I have been aware of for over 20 years, flying multiple types from twin engie turboprops to 747s, multiple variants. You can be landing fine, for 4 months, 6 months, then you will go through a month or 6 weeks of awful landings that make you look like an amateur. You just will not be able to connect, then suddenly you seem to suss it out again and every landing is a goodie, you can do no wrong, then suddenly you will slip back into just not being able to do it. Embarrassing, but it will pass. I don't understand it, but it happens!