I don’t know how best to communicate with devs so I leave this here.
Tricky issue, with harvest drag and click the fruit trees do not react, or get highlighted. However, if for some reason you do shift harvest trees on top of them, arborists will not be able to work anymore. In reality, even though the game does not communicate this to the player, the fruit trees are being selected for collection or not with this shift H drag and click.
I burned some neurons trying to figure this one out, I strongly advise to make this more clear to the player, even if at least a note written somewhere.