Could it be something related to areas of influence? Something like ref:WDPA=* located in Europe open with the URL of EEA and those located outside Europe open with Protected Planet?
Or maybe an incomplete EEA database?
Search outside of Europe, in America.
Europe:
Colombia
https://eunis.eea.europa.eu/sites/555511937
Canadá
https://eunis.eea.europa.eu/sites/4162
Brasil
https://eunis.eea.europa.eu/sites/555599966
Query OverPass on Haiti.