Not all versions of Chrome and FireFox are supported. Older versions may not be.
And this wouldn’t be the first time an update on the cloud could affect functionality. We are approaching 6 months since the last firmware update. There could be an update in a little while and they often update the cloud app before a firmware update. I use to be able to tell if there was an update by the HTML time stamp on the settings page.
But after they knocked my browsers down with the April update I stick with Roku. I only used the browsers for management and now Roku has all the functionality I need.