A Customization will be needed to make branch default to blank, because “Edit Generic Inquiry” is not an option for those in the Customizer Role:

Maybe consider building a new GI with similar fields to the above GI, and set the branch parameter to blank default.

Hi @Chris Hackett  The above post not a real answer. I know that is a not generic inquiry, hence posted a question and expected a some sample code from anyone here.

It seems there is a bug in the Acumatica, I’m currently working with Acumatica on this and will keep here posted the actual answer after my verification.

Hi @nsmith51 thanks for letting me know, when you have a solution please do post and I'll mark it as the best answer.