Look at your LuaUPnP log. ZWave delays are notorious on Vera. Look at your log, see if you’ve got the famous “got CAN” and other warning signs of mesh or device problems. Lots of threads on here about it. Make sure you don’t have any devices offline (dead batteries, etc.), but that’s not the only reason. There are many tweaks and attempts to work around the various issues. For battery-operated motion sensors, disabling the wakeup ARR/NNU is advised (see threads linked below)
To get the log, you can request http://vera-local-IP/cgi-bin/cmh/log.sh?Device=LuaUPnP from a browser (local access–put your Vera’s IP in where indicated).