Why Can't I Tip This Dispensary?

I just moved from Colorado a couple months ago and had been waiting for the recreational program to start in Ohio. I started going recently and went to Terrasana in Columbus. The service I got was great but I was shocked when they told me that I could not give them a tip. I just went to a dispensary a couple days before this and they accepted it. I'm just used to tipping at dispensaries. Does anyone know why these budtenders can't take tips here?