I have dozens of light switches, lamp dimmers and programs linked to google home via the isy portal. Been using this setup for two years, but now the device status has stopped updating in the google home app. I can still control the devices but they all just show "off".

The only change that I can think of is I updated my isy to 5.1 the other day.

Did you clear your Java cache after updating

I did, but I don't see how that would have any impact on an iOS app from getting device status updates from my ISY.

If your firmware and UI do not match, it can cause issues with the isy. Since your app gets its information from the isy, it's important that both firmware and UI match. 

I just realized you said that you upgraded to 5.1. There were some issues with that firmware. If you do not have the zwave board (if you do it must be the 500 series board) you should upgrade to 5.3. if you have the old 300 series board, you'll want to use 5.0.16

Edited December 11, 20204 yr by lilyoyo1

I have a support ticket open but thought I'd update here as well.

I've installed 5.3.1 and Google Home is still not working with my ISY.