User is getting mandate to one specific org in Oracle fusion

Summary:

Hi Team,
User is having access to maintainence orgs of A and B.
Whenever he is opening the mainteinance its getting defaulted to A. I tried to change to B and signout then sign in again its defaulted to A.
Book marked the page when the org is in B still sign oyt and sign in still its getting defaulted to A.

Normally in Manage Administration values — INV_DEFAULT_ORG_ID Profile option to default org. But we dont have this in our applications.

May I know at what basis system is defaulting to A org?

Thanks

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