Are there even books out yet for the new syllabus?
I don't want to scare you but:
Questionbanks are not only useful to consolidate memory, as of today they are a neccessity to pass the easa written exams. You will find out soon enough.
You should always fully understand the subjects, but even if you do, there are tons of questions specifically designed to trick you into the wrong answer, and aditionally a ****load of questions pertaining to random useless facts. i.e. aeroplane certified after XXX above what door threshold height should emergency slides be supplied: answers a) 1.83m b) 1.86m c) 1.84m d)1.85m. You get the drill. I've seen questions so stupid that I tought " I will never get this on my exam" and guesss what? I did. Luckily I remembered those questions by the shear fact that they were unbelievably dumb.
This is article still applies as of today:
https://dutchpilotgirl.com/atpl-question-database/. (Note: disregard the database that she's shilling in the article. As of today Avex, BGS and ATPLQ are the ones).
Don't worry, the databases will be updated in due time. They generate their content from student feedback.This essentially means that they'll need enough students on the new syllabus providing feedback before they can update their databases. Most EU CAA's still use the old syllabus, so that's bad luck for the current generation of new syllabus students, as you will be the first ones to the slaughter house. Try to remember the questions and provide feedback on Facebook groups or commercial databases, in this sense you will help the next generation, just as the previous did for us.