When I go
Top > Support > Integrity Checker and run an Extended Check I get the following warning
Warn: for doc <number>: unexpected status jump ''(Initial) => 'O'(Open) (status record <number>)
The order in question was recreated, for instance, when someone added or changed the order tax and recreated the order. In such cases PBAS does not record initial document status.
The issue was reported to the maintenance team as PBAS-24143 and will be fixed in future PBAS versions.