If the activity of a tax/GST code linked account consists of amounts allocated to it via a tax/GST code only, then the Actual Account Balance of that account must equal that tax/GST code's activity Total. Additional transactions that are directly allocated to a tax/GST code linked account will affect that account's activity. These introduced amounts will be reflected in the Actual Account Balance which will no longer equal the Expected Account Balance.
With the exception of recording your payment to or refund to the ATO/IRD, you should not allocate transactions directly to the GST Collected or GST Paid accounts.
To fix: Reverse the transaction and re-record it using the correct allocation account.