Nether portal blocks cannot replace any replaceable blocks, except fire and soul fire, when creating a Nether portal

Relates to MC-169393, MC-269974, MC-270115, MC-197126 and MC-95910. It also relates to MC-270703 and MC-261616. When replaceable blocks such as snow, light blocks, or structure voids are placed inside an obsidian frame for a Nether portal, the portal cannot be activated. Interestingly, fire and soul fire can be replaced by Nether portal blocks as expected.

Steps to reproduce

1. Construct an obsidian frame for a Nether portal
2. Place a replaceable block inside the frame, such as snow, light block, or structure void. Blocks like short grass cannot be placed manually inside the frame
3. Place fire inside the portal frame (note that you cannot place fire directly in the replaceable block due to issue MC-169393)

Observed result: The Nether portal does not activate.
Expected result: The Nether portal should activate and replace the replaceable block.