Configured dark theme resets to HA default theme intermittently on 1st gen Google nest hub unit

[dusky kettle]

I have a separate user for a Google nest hub unit, gen 1. The account is only used for this particular unit. I have configured it with a material dark theme and kiosk mode to hide the sidebar. However, every 1-3 days the configured material dark theme resets to the HA default theme.
I then have to enable the sidebar in kiosk mode, go the the user settings and yet again change to the material dark theme. The articles I find on this issue seems to advice on changing the actual default HA theme but I still would like to keep this, if possible (?) for my other users. Is there a way to resolve this please?

I should also mention that I have more or less the same setup for another Google nest hub unit where i do not see this behavior of resetting the configured theme. Apart from having also a separate user account dedicated to this unit the only difference here is the hardware where the latter is a gen 2 unit.

[prime marlin]

The setting is stored in the device cache, so something either must be clearing its browser cache, or if the device is logged out from HA that will also clear the local storage.
I know this doesn't answer your question, but maybe at least gives you some ideas to look into.

[dusky kettle]

Thanks, I will see if there is a way to keep the cache on the nest unit though I think this might not be an option. 😮 Having said that, you don't happen to know whether there is an option to "write-protect" the configured theme setting in some way?

[prime marlin]

No I don't know of any option like that