This sounds a bit like strucht auth not properly switched off. If it's switched on, but no profiles assigned in T77UA and ALL assigned to SAP* in T77PR, then you won't see any effect as long as people are assigned in Orgmgt. But when you have leavers or retirees not assigned in OM it depends on what you have in T77S0 - AUTSW - ORGPD. If it says "always reject, if no position / default position" then it used to reject despite of the ALL profile. This seems. Counter-intuitive, but al least that's what the system did at least many years ago (at least 10, I guess), when I came across the issue.
Do, cutting it short, please check AUTSW - ORGPD in table T77S0 to make sure it's really set to 0 rather than relying on T77UA being empty