After an extremely frustrating time (HA Yellow just…“stopped working” in the middle of a day) I finally got things restored…kind of. Except that HA-Y refused to recognize the ZWave stick. Despite trying to uninstall, read logs, reinstall, tweak, change USB ports and a whole lot of other VERY frustratingly poorly documented things…I finally found the answer that worked (somewhere else here): delete the device, delete everything you can related to Zwave.JS and remove the dongle. Reboot. Then reboot again with the dongle in and let it “discover” it…reinstall…Boom! All good.
Bizarre that there is no effective “complete uninstall” method documented.