VAT return not matching GL codes


Hi.  I am trying to reconcile my VAT however have a difference between the total of NC 2200,2201 & 2202 and my VAT return outstanding at the time of TB being run.

I have checked payment postings and all is correct (I thought a mis posting threw it out).  However it is a moving problem and the difference is getting bigger - not static.  I believe it could be to do with codes being changed in 2021 to make the RTD run better.  BTW I am in Ireland.

Is there a way of seeing if all my postings with VAT codes on them are making it to the nominal code?

I have checked one bi-monthly VAT report to the nominal codes - I printed them for only the months in question so as my VAT return had older items I adjusted for that.

Sales on VAT return without Intra EC = VAT NC 2200

Purchases VAT return was larger than NC 2201 but if I do the following they agree:

NC 2201 figure

- items not on VAT return when run (entered later)

+EU purchases as per VAT return

+Older reconciled (as won't show in months NC due to different date) 

These figures then agree so think this is ok and it is not my problem?

Any suggestions as to reports I could run to check etc?

Thank you