Domoticz

When turning on a switch, the status of the switch is not updated, so it stays off while the light do turns on. That is the same when turning off a switch; the light is turned off, but on the site the switch status stays on. When going to another tab, for example the dashboard, the correct status is shown.

This is not only for switches but also for the P1 smart meter counter for example.

What could cause this and is there anything I can do to fix this?

Did you update Doimoticz recently? Did you clear your browser cache as that is e VERY important step when updating. See the wiki for instructions: https://www.domoticz.com/wiki/Browser_Cache

Yes, I did update and thus cleared the cache, but that didn't help.

Although I had this issue even before I did the update...

It really seems a caching issue. Did you try another browser? Did you try a browser session in private mode?
What browser are you using? Do you have this behavior on all system that open a browser session to domoticz?

It happens in both Chrome and Edge.

I also started a Sandbox on my Windows and when turning on a switch with Edge in this Sandbox, the status is not updated. I do see the message that the switch is turned on, but the status of the switch stays off.

What kind of hardware gateway is controlling this device? As it could be that domoticz is expecting feedback from the gateway that the state has changed but not receiving it.
Did you check the domoticz log when switching the device?

Thanks for pointing to the right direction!

I was playing around with setting up a reverse proxy for Domoticz to get around the certificate update within docker and I totally missed you'll have to configure headers as well: https://www.domoticz.com/wiki/WebServer_Proxy

After configuring the headers on the Synology NAS the status are updated again.

Thanks again!