When searching for an intersection of tags
[tag-a] AND [tag-b] or the equivalent
[tag-a] [tag-b] the search results show questions tagged with both the tags. When the order of results is further set to Newest, the page will offer the in-page refresh when new items that match the filter criteria are posted.
The problem is that when using an AND filter, the "new items posted" are only filtered by the last tag in the search.
Steps to reproduce:
Search for two tags on a stack site. For example, on Stack Overflow search for
Set the ordering to Newest.
When you get the in-page notifications that new questions are posted, click it and load the new questions.
Expected: the newly loaded questions have both the tags.
Actual: the newly loaded questions only have the last tag in the search.
If a new question is posted with both the tags, then it is still going to be loaded as new, since it matches the last tag in the search.
The exact same behaviour is present when filtering for three tags:
[tag-a] AND [tag-b] AND [tag-c]will only show updates for [tag-c].
I am certain the position in the filters is the key factor. Changing the order of the search to
[tag-b] AND [tag-a]will show updates for
Same behaviour is seen in custom filters.