Following the instructions in the Auth0 WordPress plugin installation guide (using Option 1), I attempted to use the plugin on a WordPress multisite network. The plugin works correctly on the main site; however, on the subsites, the “Enable Authentication” option remains disabled (greyed out) even after configuration and saving settings.
Please see the screenshot below for reference.
As a workaround, I enabled cookie sharing across the network for authentication.
However, this is causing interference with a separate subdomain that is not part of the multisite network, since the cookies are applied at the root domain level and not limited to the multisite.