Have you watched the hub's live log while doing a z-wave repair? You should be able to see on which node the repair appears to be getting stuck. Then check your hub's z-wave settings page to see which device corresponds to that z-wave node #.
If not, I would try that first. Less tedious than disabling individual devices and re-running the repair over and over again.
Tried that but all devices/nodes are very slow. When it worked I noticed that when I just unplugged a z-wave device they all responded the same way in the repair - all became very slow.
Unfortunantley I can see, that in the logs the repair still includes the devices that I disabled...
Have you tried shutting down the hub and then pulling the power for 30 seconds? I donโt believe that a reboot shuts down the radios (if youโve tried that).
FWIW, I went crazy for months trying to diagnose a persistent hub slowdown. It improved when I got rid of my three peanut plugs but it has been solid without a hicup for a few weeks now after I disabled my z-wave Aeotec Heavy Duty Switch I have been using for a "dryer is done" notification. I changed to driver to generic z-wave switch and X'd it out. I had previously removed it, reset it and repaired it to no avail. I think it spews too much constant info for the hub to digest. Enabling it slowly brings the hub to a crawl in a day or so.