This issue seems to be old but I found this bug in my world in April 2023. If anyone is a little new to this workaround, I was still able to fix it after trying many suggestions I found online.
Get the program NBTExplorer, open it. click on the world where the end portal isn't generating. See if all 20 entries are listed.
In NBTExplorer, it said there were 19 gateways, so I added an entry. If I used the original locations of the same seed, the world just deleted the last entry after the dragon fight. So I took down all the existing portals, in creative mode. I went back in and added an entry in NBTExplorer. This time I used a list of entries from a completely different seed, and changed all the numbers to match it. The portals are now generating after the fights.
stillinhere
This issue seems to be old but I found this bug in my world in April 2023. If anyone is a little new to this workaround, I was still able to fix it after trying many suggestions I found online.
Get the program NBTExplorer, open it. click on the world where the end portal isn't generating. See if all 20 entries are listed.
In NBTExplorer, it said there were 19 gateways, so I added an entry. If I used the original locations of the same seed, the world just deleted the last entry after the dragon fight. So I took down all the existing portals, in creative mode. I went back in and added an entry in NBTExplorer. This time I used a list of entries from a completely different seed, and changed all the numbers to match it. The portals are now generating after the fights.