Tax Amount Disappearing When Saving Credit Memo

I have searched the metalink and observed there is Doc ID 2087817.1 that talks about similar issue. But that was in 12.0.5 and we are currently on 12.1.4.

i believe there is no need to deploy the patch especially knowing we are not having this challenge for all the Credit memo's. The Transaction Type is also properly defined.

When we go to the Credit tab the form displays the Tax Amount available for credit and allows us to select the same but while saving it just converts to $0.

Thanks, Vivek