SERVER-89443 introduced a new JS test whose teardown phase includes a call to sh.awaitCollectionBalance(): such a function is not usually invoked outside FSM suites - and it seems to be incapable of managing write errors raised when contacting a stepping down CSRS (even though retry logic is apparently already in place). Due to this, the test has been temporarily blacklisted from stepdown suites.

The objective of this ticket is to perform a RCA of the problem (and if possible, remove the test blacklisting).