To add a bit more information: My date fields in the sync table are date fields with a friendly date format. The other table is date field European style. Could this be causing the issue?
First off, the date format change could definitely cause an issue, I'd either friendly the date field in the SDK table or write a quick formula to convert the friendly into European in the sync table and use that to feed the date.
Secondly I think I'd need to see the Find records automation to see what's being pulled in to create your list. Right off the bat unless there's something hiding in that Find automation, you'll end up creating duplicate records every run. You could fix this by adding a checkmark field in your sync table so that after record creation, each record is updated to checked, and then a condition in your Find is "unchecked". I'm also wondering about primary fields in both tables, are they short text fields? Do the short text fields frequently overlap?
To add a bit more information: My date fields in the sync table are date fields with a friendly date format. The other table is date field European style. Could this be causing the issue?
HI,
More important part of information is config of Create record step, at least part of it with date. I think, you did a wrong choice of a source data.
With proper config, date format should not be the issue. Airtable stores all dates in ISO.
As long as it a single date. List of dates is a string, that cannot be parsed to a single date value.
What you see when change format is just different visual form, data remains the same.

Could you confirm that you're using the values from the 'Current item' like so? Your screenshot shows the record being created with multiple values so that might be an issue. If you're already doing that, could you provide more screenshots of your automation setup?

With a lookup field displaying a 'Friendly' date I'm able to put that value into a 'European' format date field with no issues:

Link to base