Randomly losing Profile page content in WordPress

WordPress 5.4.1 Civi 5.25.0 Debian 10

We are randomly loosing profile pages in WordPress... The WordPress page is still rendered, but without any of the Civi Profile content (Profile is embedded as a shortcode in "Edit" mode). Clearing the cache with "wp civicrm cache-clear" multiple times (i.e. more than once, sometimes 3 or 4 times) resolves the issue and profile forms are shown again. Deleting the tempaltes_c contents doesn't immediatly resolve it, so we think it's possibly an ACL cache issue in the DB. We have ACL entries for "everyone" to view the profile and edit underlying custom field group, and the profiles can work fine for a day or two, then suddenly vanish without any errors. Any help, much appreciated as this one is proving really hard to debug.