Assignment Blocks getting greyed out on certain change document statuses

Hi ChaRM/Solman Experts,

Currently in the process of implementing ChaRM on 7.1 SP11 and running into an interesting scenario. We have some custom statuses in Normal Change and Admin Change and as soon as those Custom Statuses as selected, the Document Assignment Block (Solutions and Project Assignment block) is no longer available to edit and once the change document is back to out of the box Statuses, they are editable.

Here is a sample when they are available

And not available in Custom Status

In SPRO I found an activity which says what Assignment blocks to make mandatory based on a charm transaction type and associated document status. I guess there must be some level of customizing somewhere to say what blocks are available on what status. Really appreciate your assistance.

Regards,

-Anshul