I had this multiple times in the past. This time it is Header P11.
If i move P11 out of the board outline copper area fill is working like it should.
![working.gif](//image.easyeda.com/pullimage/zuNvc6YKVrQpo5Ws1tjhTGZc0qpxMVY93dOKJAix.gif)
After placing P11 on the PCB the copper fill stops working.
![not working.gif](//image.easyeda.com/pullimage/14djZlkp1WjpLJTVHMASFWJu60A3sBHQSJzmH3MX.gif)
Strangly when enabeling the island they still apear but the rest of the fill does not exist.
![island.gif](//image.easyeda.com/pullimage/N6Z4u3MeAX67MvHUQcuSWNqhzu6amyscoFScoGXG.gif)
Vivaldi
1.93.955.48
Windows
10
EasyEDA
5.8.20