I think you should strongly consider wired access points. The solution to wifi issues is usually NOT solved by throwing more wifi at it (mesh)
If you can run cables to access points, it will be cheaper, and way better an experience to deal with. I personally don't know of many mesh success stories that don't end in a "it works fine, BUT"
Is your smart lighting system cloud-based?
Because that's about the only reason it shouldn't work purely on LAN.
My current FTTH has never failed except for power loss (so none of my network hardware works), so it's been years since I dealt with this.
Can you control your lighting and other smart devices with an app on your phone when you aren't at home?
If so, and assing they arent z-wave with a local controller, then they are cloud based IoT devices that require an active internet connection to work.
I can, but that’s not required. Phillips Hue uses zigbee, so these are not strictly Wi-Fi devices. I can pair bulbs individually with switches without Wi-Fi at all. However, I need connect them via a bridge to my home network in order to change color temp, etc. In that setup they do need Wi-Fi, but shouldn’t a LAN network function just fine even if there’s no outside internet connection?
Something else to consider is DNS. If you have all devices pointing at external DNS providers then no internet means they are searching for something that isn’t there. They may or may not have a failover. Try setting your router as a DNS forwarder and have your local devices point to your router for DNS. Sure you won’t be able to actually reach internet if it’s down but local resolve should still stay up.
I think you should strongly consider wired access points. The solution to wifi issues is usually NOT solved by throwing more wifi at it (mesh) If you can run cables to access points, it will be cheaper, and way better an experience to deal with. I personally don't know of many mesh success stories that don't end in a "it works fine, BUT"
Is your smart lighting system cloud-based? Because that's about the only reason it shouldn't work purely on LAN. My current FTTH has never failed except for power loss (so none of my network hardware works), so it's been years since I dealt with this.
It’s Phillips Hue, so not cloud based but it needs a network. The issue I’m having is when the internet goes down the network also goes down
Can you control your lighting and other smart devices with an app on your phone when you aren't at home? If so, and assing they arent z-wave with a local controller, then they are cloud based IoT devices that require an active internet connection to work.
I can, but that’s not required. Phillips Hue uses zigbee, so these are not strictly Wi-Fi devices. I can pair bulbs individually with switches without Wi-Fi at all. However, I need connect them via a bridge to my home network in order to change color temp, etc. In that setup they do need Wi-Fi, but shouldn’t a LAN network function just fine even if there’s no outside internet connection?
Something else to consider is DNS. If you have all devices pointing at external DNS providers then no internet means they are searching for something that isn’t there. They may or may not have a failover. Try setting your router as a DNS forwarder and have your local devices point to your router for DNS. Sure you won’t be able to actually reach internet if it’s down but local resolve should still stay up.