Restoring the correct value of wp_user_roles in the database works around the problem. Activating live links on a site b0rks the value of wp_user_roles in the wp_options table, replacing any subsets with the value ‘Array’ as mentioned by @surajv in November. Currently using 6.2.1+5711.
The issue is that the replace_host method in the must-use plugin local-by-flywheel-live-link-helper.php usually receives three strings, but in some instances, the value of $subject is an array, not a string.
(cc. @ben.turner.)