Strapi Admin Panel custom role permissions resetting between sessions

Strapi Admin Panel custom role permissions not saving between sessions

Every time I set role-specific permissions on the admin panel (i.e. tickmarks in the image below) and hit ‘Save’, the ticks are saved. When I log out and log back in the next day, all ticks are gone and my admin users do not have the permissions they need. Does anyone have any idea what might be happening here?

Many thanks!