In the debug logs , any time super admin would list customers it would throw an error from
\MySLP_User::load() saying could not load blog for user #310.
Turns out this was caused by user 310 (cici) not having an associated site ID as it is a super admin account. Set the fallback to point to the main site (Site #1) when super admin does not have a site id.
Fixed in MySLP Dashboard 2503.04.01 and MySLP Architect 2503.04.01.