Being new to any type brings this up: To start with you are concentrating on merely controlling and flying the aircraft and using your whole brain to do so, and you can do a good job.
Then, as the days/weeks go by your brain starts to think about other things - the wider picture - and all sorts of other considerations to do with the new type/routes/operations etc. It needs the conscious part of your brain for this, but the ‘motor program’ for landing has not fully developed yet, so your ‘CPU’ has to divide its time between several tasks.
Do not stress, your landings will come back. I find the Rad Alt aural call-outs to be most useful when landing
