Broken End Exit Portal was unable to Respawn Ender dragon Using The Ender crystals

As I was playing Minecraft, I traveled to the end to kill the Ender Dragon a second time. When I got there the entire portal was gone. I attempted to rebuild it with the materials it originally came with, In there exact spots, But I was unable to summon it a second time.
Whenever I tried to place the End crystals in the percise Block for respawning the End dragon after a fixed portal, I expected it to resummon the End dragon like normal.

In return of me replacing the bedrock blocks where the portal origionally was and thenso placing the Ender Crystals on the 4 blocks of the portal, no event was triggered to signify that I had done anything at all the respawn the Dragon.
All the happened afterwards was that the portal was still stand with the Ender crystals in the right positions, nothing else.

Steps to Reproduce:
1. I regenerated the end island do that I could fux all the broken parts of it
2. Part of the portal was destroid and would not regenerate with the rest
3. I replaced the missing bedrock blocks with the original block, Bedrock
4. Attempted to summon the ender dragon with the 4 Ender Crystals
5. No event happened afterwards to signify the respawning was triggered