EBS R12 Lost Responsibility while navigating

 Hello All

I navigated away from the EBS (12.1.3) home page to an Accounts Receivable page and on return had lost all my responsibilities - I had to log off and log back in to regain my responsibilities - However, I could not replicate the same again EBS Home page > Receivables User PV > Cash Application Work Queue. 

Other users in my organization experienced  the same issue number of times.

Any reason or fixes?. 

Regards

Amit