The ‘Revised’ status is assigned when copying a proposal.
During the copy process of a proposal, if the ‘Set Original Proposal with Revised’ option is checked, the original proposal becomes un-editable and receives a status of ‘Revised’.
This is not a bug but a misunderstanding of the 'Revised' proposal status, which is typically assigned when copying a proposal.
When a proposal is set with the 'Revised' status during the copy process, by checking the ‘Set original Proposal with Revised' box in the copy popup, the logic no longer allows that original proposal to be edited, as it's now considered 'old' and the new copy will be the working proposal going forward. This is the intended functionality for 'Revised' status. And 'Revised' proposals are only listed in the Proposal list grid when the 'Show Closed Proposal' checkbox is checked.
Note: If the user wants to create an exact copy of a proposal, but keeps the original proposal editable, then they do NOT check that ‘Set original Proposal with Revised' box on the copy proposal popup.