I thought it was maybe a mesh problem but the c8 hub is sometimes not controlling switches that are directly connected to node 01 (the hub) and only feet away from the hub.
I migrated my network from c7.
Firmware is up to date.
Is this forum the only source of support?
There is official support at support.hubitat.com (you'll also find a link to it in various places), but here is often better because staff read the forums too. Sometimes you'll get help directly from an engineer or at least faster response from knowledgeable community members.
I'd start by sharing a screenshot of your entire Settings > Z-Wave Details page. The things people might look for are "bad" stats for any of the devices, ghosts, or other possible problems. If you want to try some troubleshooting on your own, I'd start with: How to Troubleshoot Z-Wave | Hubitat Documentation
How is your hub getting power? PoE power splitters have been known to cause Zwave issues among other things. Mainly when using Unify gear as the PoE source for some reason.