Sorry to hear about the problem with Netflix, looking forward to seeing all the countries back soon. If there's anything I can help with (tests, scripts, VPNs in Central Europe), I am ready.
Regarding Greece and the problem with Superman. Could be this problem related to different profiles?
Some titles are accessible only when you select the profile with a specific language even when your account is one country. I had the same problem in the Czech Republic when Netflix last year came with full Czech support.
1.) When you have the profile with the Czech language, you are able to see and search only the titles with Czech subtitles or audio (only about 30% library in the Czech Republic.
2.) When you have the profile with the English, you are able to see and search only the titles with English subtitles or audio. So for example, if there's a Czech movie with no English audio or subtitles, you are not able to find with English profile. The problem is for 20-30 titles right now.
And just for fun. If you want to access the URL from case 2, for example, https://www.netflix.com/title/81192071 from outside the Czech Republic and not logged-in or with the script with no CZ header, it will show you 404.