Probably not specific to 1.89 but yes yet another Sentinel bug.
Friendly Slithar minion, Enemy Vanar Freeblade (sentinel that switches place with summoned enemy=.
Plasma Storm is played. Killing all minions. However, instead of being killed Vanar sentinel switches places with the egg (which should ofc happen after plasma storm effects are processed) and then resurrrects as Freeblade.
These sentinel interactions are still so messed up it is discouraging that the idea even left the drawing board. Please fix.