Probably linked to T262234. But if I understand the explanation by @Samwalton9:

We follow Twitter's specification for what constitutes a hashtag, which includes not flagging it if there is no space or punctuation before the hashtag

I think it should anyway detect hashtags after a | inside internal links, for the reasons explained above (really useful and common on Wikipedia to use an hashtag and make a link to the project using the hashtag).

I second this request. Three of my tools (Proveit, Synchronizer and WikiEdit) would benefit from it.

Hi, good news! I was able to add valid hashtags to links by simply adding a space before the # (so as to satisfy the Twitter's specification of a hashtag) like so:

[[Example| #example]]

Good enough for me!