[Fern]

Retaliate, the Matador skill, can be used while immobilized.

It acts similar to Hanging, which is stopped while immobilized, so we are assuming it's a bug/oversight.

[Autumn]

A raging bull can break free of this binding

The issue is with Stampede not retaliate.

So I'll just say that disabling the range buff from stampede while immobilize is active is good enough so that its not that retaliate just straight up can't be used while immobilized.

[Neus]

I don't know if this really qualifies. Retaliate isn't a movement skill, and Immobilize doesn't stop effects that move you.