LG LF652 not showing some photos fullscreen

Hi, i have an issue with the above mentioned TV that it is not showing the pictures with higher dimensions (mostly from DSLR) fullscreen. Pictures from cell phones and older cameras are shown fullscreen. I also tried to use different profiles but that did not help. Also didnt find any similar topic here.
Other media servers like LG smart share are showing the pics fullscreen no matter how big they are.
Thanks for any hint.