BF-37960 is an issue where an invariant is hit on wiredtiger_kv_engine.cpp when a mongod tries to shut down. It happens on KMIP server doesn't respond to the request to fetch the encryption key in time when wiredtiger_open is called. 

This issue likely occurs in v8.0-s8 branch due to Straight to 8 exposing different FCV pathways that could enable a downgrade to happen. It could possibly happen in this check in shouldDowngrade(), since right now the FCV is being started on 7.0 (the kLastContinuous and kLastLTS but the mongod starts on 8.0-s8, whereas on master, both the FCV and mongod are 8.0.