Custom portal blocks don't seem to generate when you save them as a structure together with a custom portal.

So I am working on a Mod, where I made a custom Dimension and i wanted it to only be accessable though custom Portals that spawn as a structure in the Overworld and in the Dimension.

When trying out the Portal for the first time, only the frame structure generated, not the Portal Blocks.

The Portal Blocks do not have an Igniter Item and have Air set as Frame Block.

The frame structure is an irregular shape for a portal, so I used /setblock to spawn the portal Blocks and a debug stick to rotate them.

Is there any way to get the Portal Blocks to generate, and if yes tell me what I did wrong and how was I supposed to create the Portal Structure so it would generate.

I do know that Portal Blocks are very very sensitive and destroy as soon as the block next to them is gone or updates. 

Does this mean that It is impossible to generate Portal Blocks, since they destroy because of Blocks that spawn next to them leading to BlockUpdates?

Please answer quick, since this is very important.