Let's review what is happening here, st-thomasmorepar.
Duplicates might come from the Banking page or a recurring transaction template. Let's see which one is causing the unidentified postings.
There might be bank transactions that were Added instead of Matched . Here's how to check the transactions:
You can also use this link for reference: Categorise and match online bank transactions in QuickBooks Online.
If everything is categorised correctly, we can review the recurring templates. Here's how:
You can also browse these links on how to manage the recurring template:
For the duplicate transactions that occurred due to the recurring templates, you'll have to delete them manually.
We'd like to know more about your concern if none of what I've mentioned above suits your situation.