Evokers can't summon fangs or vexes when they are standing on top of ice

Evokers are completely unable to summon fangs or vexes when they are standing on top of ice even though they still raise their arms. Why do they raise their arms? Evokers should still be able to attack when standing on top of ice, so this needs to be fixed.  Silentwisperer just told me about it and said I should report it.

Steps to reproduce

1. Make an ice platform
2. Spawn evokers on top of it.
3. Spawn villagers

Observation: Evokers raise their arms and don't summon fangs or vexes.
Expectation: Evokers raise their arms and summon fangs or vexes.