TL;DR PlanCacheKeyCollectionState::version may be different across shards to the same collection when sharded. This causes planCacheKeyHash to be different, which makes the test fail (as it expects hash to be the same).

In case we assume this value should be the same for all shards and be kept in sync then we need to investigate why it is different and fix it, otherwise mark as "works as designed" and rewrite the test to not rely on this assumption.

Detailed description of the problem could be found here