Inventory- Blank location is flipping back to the Primary

Hi

In 9.1when I am doing inventory transaction i.e adjustment, issue and at the time of transaction when I select the location which is secondary location and that is blank, it does not save the blank location instead of that it changes from secondary to primary in 9.1 (flip back to primary) but if i create a location with dot (.) then it save the location. Just to let you know we don’t have location control turned on. In 8.0 this is not the case even if the location is created as BLANK and I select at the time of transaction it saves as blank location.