Bit of a convoluted one this: if I have a Multinode Treepicker inside some nested content then the "Minimum number of items" rule is ignored when the content is first saved. Any updates to the items will get flagged and won't save, as expected.

I'm using V8.15.1

Here's what I did.

1. Create a new MNTP datatype with "Minimum number of items" set to 3. Leave the max at 0.
2. Create a new document type with a field that uses the new datatype. Set as an Element Type.
3. Create a new document type with a field that uses Nested Content. The configuration needs to allow the MNTP document type. Allow as root.
4. Create content that uses the Nested Content document type. Add a nested content item. Select 0, 1 or 2 content items in the MNTP. Content can be saved and published with under the minimum number of items.
5. Navigate to another page and then back to the new content. Add or remove MNTP items, keeping the total under 3. Content cannot be saved - you see the red warning, as expected.

Anyone else seen the same thing? It works when the MNTP is just a field on some content (although the warning is different on initial save, compared to update).