Posted 13 March 2018 - 07:31 PM (#3)
yes I did a "Refresh", but it didn't help. To me this is a new problem, because (from my point of view) it came up with build 1765.
Quite interesting is the fact, that I observe this issue only with groups created in 1765. Older groups still correctly show the 'group' icon in the upper right corner of the thumbnails.