Guild Wars 2

The trait should give you +15% movement speed as long as you have a dagger equipped.

I tested with a stop-watch and double-checked against using Signet of Air (+10 speed) with the result, that, dagger or not, this trait does not change your movement speed at all.

I can confirm that disabling auto-attack for the skill does not make this bug go away. I have mine on skill 6 and still see channeling being stuck.

There’s an easy workaround though: just use the key-bindable “sheath weapons” when the bug hits.