Is the antenna near anything that would be giving off interference?  I had a job where I moved the antenna about 10' from where I initially put it and the performance went from OK to perfect.

I'm standing in the house where I'm having this exact issue right now.  In my case it's absolutely a range issue.  There is an electrical subpanel in the room and it's killing my Zigbee and WiFi signals.  1 step out of the room and it works perfectly.  I had to put a ZM24 right in that room to get it work.  However, if you have multiple ZM24s you have to make sure the remote is actually talking to the closest antenna.  If I take this remote from the basement to the room on the 2nd floor where I'm having trouble, it still talks to the basement antenna.  That's when I get skipping and repeated commands.  If I reboot the remote in that room, then it locks on to the ZM24 that's about 8 feet away from it and it works perfectly.

Do you have just one ZM24 or multiple ones?

edit - should have mentioned this happens on three different T2-CZ's