Rename with 'Contents Match' often gets year wrong

We have a number of rules to match just-scanned documents which have been OCR'd by Abbyy. For our receipts, there are many different variations of date format, e.g. DD/MM/YY, D/MM/YYYY, etc.
We use Contents Match rule with a Custom Date which matches one of the patterns, and then put a "Rename ..with the pattern" action on it to prefix the filename with the date discovered inside the file. Often, the date prefixed will end up as '2020' even though it should be 2016. It's inconsistent, but I have some PDF files that reliably reproduce this.
Seems like a bug - anyone else seen this?
We use Contents Match rule with a Custom Date which matches one of the patterns, and then put a "Rename ..with the pattern" action on it to prefix the filename with the date discovered inside the file. Often, the date prefixed will end up as '2020' even though it should be 2016. It's inconsistent, but I have some PDF files that reliably reproduce this.
Seems like a bug - anyone else seen this?