Calculated date fields fail in automation filter block

I search for records in an app based on dates. The date fields in the records are calculations, as they pull a date field from a referenced record.

The UI seems to correctly recognise them as date fields as it offers “is after” and “if before”. Instead of 17 expected records, the result is only 3 records.

I copied the calculation date fields in real date fields. I then get 17 records in the search as expected.

I guess that onfirms its a bug?

This is the data:

Maybe this helps: Converting this block into a script shows, that the calculated date fields are

field_type: 'CALCULATION',
type: 'calculation',

But maybe should really be:

field_type: 'SINGLE_DATE',
type: 'date',

for the date filter to work correctly?