According to sun position of globularists, Lisbon sun sets earlier. And in my opinion Lisbon sets earlier too. Hence the sun setting isn't the case.
According to globularism:
Sunset Lisbon: 20:54
Sunset London: 21:01
According to my map: Logical. Hence it is not the case.
You made the map before collecting the data, it should be the other way around. I'd suggest you forget about the "globuralist" map as you call it and start collecting data, then make the map when you have enough data. Once you have something solid compare with the globuralist map:
1. For best results forget about webcams and travel to the places and make pictures or contact other fellow flatearthers around the world you can trust to make pictures for your map.
2. Pictures must be comparable: Sunrise or Sunset on the horizon, horizon at same level in all pictures (sea or at least flat plains), same time in the year (even better same day) no obstacles impeding your view like buildings or hills.
3. If webcams are your only option, make sure the camera shows time an date and look for webcams looking at the sea with view of sunrise or sunset. There are plenty of beach webcams for surfers and tourist, you just cannot expect sunrise on the beach in Portugal. London has too many buildings, pollution and fog, not the best choice either.
I have another webcam for you. That's a sunrise on the sea viewed from Barcelona. Expected at 6:39 (5:39 GMT) according to globuralist map:
https://www.skylinewebcams.com/en/webcam/espana/cataluna/barcelona/playa-sant-sebastia.htmlEastern Spain is better for sunrise, Portugal for Sunset. The are some good webcams in the Canary Islands as well.