I have one simple query that’s in my activity (currently active) that’s in there 5 times. It should have closed very quickly, yet there’s 5 instances idling. I have two other queries, that should have operated quickly, then closed, but they are idling.
Queries don't idle. Only sessions can be idle - either normally or while holding an open transaction. An idle session will have a "last executed query" which may be confusing you. You should probably post the actual results of pg_stat_activity along with your comments so as to help rule out mis-identification.
