Inconsistent results from cause filter in RECAP Search

[albertisfu]

We received a report about a user not being able to get the expected results from the cause filter.

https://www.courtlistener.com/?q=&type=r&order_by=score%20desc&cause=%2231%3A3730%20Qui%20Tam%20False%20Claims%20Act%22

The query doesn't return any results.

Filtering using a fielded search does work.
https://www.courtlistener.com/?q=cause%3A%2231%3A3730%20Qui%20Tam%20False%20Claims%20Act%22&type=r&order_by=score%20desc

So the problem might be related to the type of query used for the filter, where some terms break the query.

A partial query, removing terms from original query in the filter, also works:
https://www.courtlistener.com/?q=&type=r&order_by=score%20desc&cause=Qui%20Tam%20False%20Claims

[mlissner]

Looks like the colon might be to blame. Since we have a workaround, I think it's OK to continue on your API work and then get back to this during a cleanup round.