While I don’t change reactions on my site a ton, I do change them from time to time.
My users are reporting the 
reaction seems to auto convert to 
I was able to reproduce the issue.
I tried changing the order of the reaction, same result.
I’ve removed the wave reaction, at least temporarily.
Not a huge deal, just mostly curious if I’ve changed configurations in a way that would cause this outcome.
Thanks!
Is the goal here to remove ? or are you simply trying to add a reaction.
Sorry if it wasn’t clear.
I have 8 reactions, of which hand wave was one.
When users selected hand wave, it appeared briefly (enough to be seen and not enough time really to screenshot) before the wave changes automatically to a heart.
My plane today was to re-add hand wave after having it not as a reaction and see if it made any difference.
My suspicion is that either due to addition, removal, and shuffling of reaction positions over time that (for whatever reason) wave is not recognized and so is being substituted as a heart.
Wish I had more useful information to offer.
Is it possible that you have the hand wave reaction set on the Discourse reactions reaction for like site setting?
Great thought.
I checked and
Discourse reactions like icon is set to heart, as is
Discourse reactions reaction for like
I do see Discourse reactions like sync enabled is unchecked, to the best of my knowledge that is the way it has always been set.