The bug
You can spawn a unarmed vex with this command:
/summon vex ~ ~ ~ {HandItems:[{},{}]}
This summons a vex that yields no weapon. When switching to survival, the vex glows red and notice that the vex is raising its arm to attack which it looks offensive.
Linked issues
Attachments
Comments 2

Those issues are in bedrock too it need to fix in bedrock.
In 20w29a