Thanks everyone for your advice. So I have three of the IRIS v3 sensors set up, two in my Master Bathroom (one in the main bathroom and one in the commode room).
What I've noticed is that the lights don't always turn on in the Master Bathroom with motion. They work most of the time - about 80% of the time. Either the Zigbee signal is not getting to the Hubitat quickly or the Z-wave signal isn't coming from the Hubitat back to the switch. The switch for the Master Bath lights does work.
I have an additional problem in that the Leviton light switch in the Master Commode room has, once again, lost its connection with the rest of the network. I can see from the Devices details page that it's last activity was on 5/12/2021 even though it should have turned on in response to motion or responded to Alexa many times after that. It does not respond to Dashboards or Alexa.
I've searched for Ghost Nodes and made sure the firmware for all Leviton switches is up to date (was finally able to get this accomplished today - Yay!). Unless there is another possibility, I'm guess that the Master Bathroom, which is on the North side of the house, is probably not getting Z-wave/Zigbee signals in and out very well.
I have Philips Hue light bulbs in the next room (the Master Bedroom) which I believe are Zigbee and work just fine. I also have an Aeotec Z-wave extender in the Master Bedroom. In fact, I have several Z-wave extenders between the Master Bedroom and where the Hubitat Elevation is located.
So now my question - should I buy another Z-wave range extender + Zigbee range extender for the Master Bathroom itself? Is there an extender that combines both Z-wave and Zigbee? Will it be compatible with my existing Aeotec Z-wave range extenders?