Not sure if you are still looking for a reply, but I've just encountered the exact same problem with my Honeywell zone valve. It's the 8043 model and it is brand new, replaced because the previous valve was sticking.
Our repair techs couldn't track down the problem so I ended up having to learn the whole system myself to diagnose this. Yes, the gear will move and open the valve, but will not touch the actuator switch with enough force to depress it. Very annoying problem. I currently have a washer taped to the lever to bring it closer, but even that is an intermittent solution. According to the videos I've seen online, replacement is recommended. Good info from the video below: (if they will let me link here, not sure) It is on YouTube under "Port valve diagnosis and repair".
I am likely going to replace the switch, but first I'm going to try WD40 on the gear box to see if it's just slightly sticky. I've already given Honeywell a blast over this one. They were terrible with their tech support for me when I was looking for the problem. My gear lever will touch the actuator, so it looks completely functional, so it was quite tricky to figure out. Our valve doesn't require purging the system, so replacement is not going to be too bad. One plumber said if the the unit has a 'nipple' on the case, ( a small protruding, rounded button sticking out of the flat metal surface) it means that it can be swapped out dry. Not sure if that's the case or not. There are good videos online about doing the repair, though.