I know I'm far from first to report this but I would like to add to the rumors that wired network gear interferes with Hubitat radios. When I moved to the home I'm currently in about 5 years ago, I didn't do much planning before I started running wires. I took by force a wall in my wife's office closet to mount an all in one Asus wifi router. Not before long that wall was filled with Unifi network gear, audio amplifiers, UPS battery, and of course Hubitat. With almost 30 Cat6 runs into the closet, moving everything to a more suitable rack was something that got put off for... years.
Well finally it is done: additional switches around the house eliminated, everything wired back to a proper rack, and physically seperated from Hubitat. In fact, the only pieces that remain in that closet are Hubitat and a UPS.
Since moving all the network and audio gear away from Hubitat, EVERY single ZWave device is directly connected to the hub. If you suspect your radio performance could and should be better, and Hubitat lives near network switches, try moving one of them.
For those interested, this is what I built in my office. I cut out a section of the wall that backed up to a crawl space and made room for a rolling rack. It's about 80% done, just a little trim work and painting left. I am rather proud and happy with the result!
This is the mess of a closet I was dismantling, but its an old photo with different gear.