I guess, I found one problem for the "Include ONLY" URLs: option.
I got two strings in the field, seperated with space:
:: and /en/
This apperantly does not work. I thought, if I use two strings, it would work like including only the URLs which match both strings.
If put only the string /en/ in the filed, I got a sitemap with only the english URLs, but also URLs without :: in the string are included. So each string for itself works, but not both together.
About the other problem with the "Exclude URLs:" withe the same string option ...
With this option 0 pages are indexed.