Modern Team Sites - Highlighted Content filtering issues

Hello,

I'm trying to work with the modern Highlighted Content web part to display announcements that have not expired.

I started my experiment by adding the classical Announcement "app". I was able to filter out elements from this list by filtering on managed properties in the highlighted content web part settings by using "ContentType" and literal text matching "Kunngjøring" (the norwegian content type name - I realise this is probably not the best idea but bear with me for a minute).

I have not been able to filter on date properties. I have tried "Created", and "Modified". There's also the managed property "ModifiedOWSDate", but it's apparently in text format when I try to set a filter expression for it. My site's regional settings are set to Norwegian, I have a feeling this is part of the issue. When I try to set a fixed date in a filter expression according to the format (DD.MM.YYYY) there's a validation error message for the field. As I set it to MM/DD/YYYY the field validation error is not shown, but the results are not filtered.

So, after struggling with this for a good while I decided to try and create a new yes/no column that I could filter on. So then I realise I probably need to create a managed property for this. After creating a new managed property and mapping the crawled property of the yes/no column, it does not get included as a choice when editing a new highlighted content web part. I tried creating a brand new page in case there was something odd. Now I'm not sure if I simply need to wait a bit longer for the managed property to be available or if there is something else causing it not to show up.

Thanks for reading, I would appreciate any suggestions.