Got some problems in Idea 2020.3 & Cursive (stable or EAP) and latest clojure/tools/clojure@1.10.2.790 Symptoms: can't see any modules in Clojure Deps tab in Idea. Also can't start remote repl. Downgrading to clojure/tools/clojure@1.10.2.774 solves the problem.
I don't know whether alexmiller uses Cursive or not, but if not, perhaps letting Cursive dev on #cursive know this might help get to root cause.
Are there messages in the IntelliJ error log?
It is possible that the cache file format change is not properly picked up in the cursive scenario - rm ing your .cpcache dir would help if that’s the case, but just guessing