Hi Lincy,
This is not exactly 'strict' control in SAP terms. Strict control is activated with AVC ledger and not by changing profile. If you, however, have 'usual logic' for AVC, then it's normal that you have no messages for old PRs, as your budget consumption does not change: PO commitment eliminates PR commitment, but does not create additional consumption.
'Strict logic', once activated, would issue AVC message even if consumption does not change. But, as I said, this has nothing to do with tolerance profiles setting.
Regards,
Eli