This is going to take some explanation.

Every month I import a QFX file from my credit card accounts (different companies) and each time it results in a grossly mis-matched entry in my checking account on the transaction that represent the current month's payment to the credit card.

Ubuntu 19.10 / Cinnamon 4.0.10 / KMyMoney 5.0.6
Accounts in question: 1x savings, 1x checking, 2x credit cards

ACTIONS:
1. Open KMyMoney (All accounts are already reconciled from the previous month)
2. Enter all new transactions into the account ledgers
3. Enter the current credit card payments (using the scheduled transactions)
4. Save the .kmy file and close (to ensure a clean starting point)
5. Download the .qfx for each account
6. Import the .qfx for savings and checking (same bank)
7. Reconcile both accounts (all transactions are matched and accepted without problem)
8. Save the .kmy file and close
9. Import the .qfx for credit card #1 (This is when the problem arises)

PROBLEM:
The importer duplicates a cleared credit card payment transaction in my checking account from nearly two years ago and matches it to the most recent payment in step 3, even though the amounts don't match. This happens during a QFX import from either credit card account. This mismatch only happens in the ledger of the checking account. The credit card ledgers never have a mismatch and reconcile cleanly.

WORKAROUND:
To correct the error, I have to un-match the transaction, locate the duplication of the old record and delete it. The newest record is the current uncleared payment that must be kept or the balances on both accounts will be off during the next reconcile.

Does anyone know what may be causing this? A problem with the scheduled entries? Are there known issues with QFX files?

Thanks in advance!