Joe Jonas and Sophie Turner Had Problems After Birth of 2nd Child

Sophie Turner was struggling after the birth of her second child, and Joe Jonas was "less than supportive," so claims several sources who were around Joe after the birth.

Our sources say, after their youngest child was born a year ago July, Sophie didn't want to leave their home ... she didn't want to be photographed or go to events. Nevertheless, she attended several events with Joe, but at one specific event, several people who were there said Sophie made it clear she was uncomfortable and didn't want to be there.

Shortly after that event, there was another in which Joe attended but Sophie didn't. Our sources say Joe complained Sophie was MIA and felt she needed to get out more. It was clear to the people who were there and heard Joe ... there was a strain in the relationship.

What's interesting ... as we reported, over the last 6 months it seemed the tables had turned for Joe ... he was complaining she was too into partying.

Sources connected to Joe acknowledge "challenges in the relationship," but say Joe was supportive of Sophie getting the London acting gig.

As we reported, Joe filed for divorce Tuesday ... and the trigger for him was allegedly Ring camera audio/video of Sophie doing or saying something.

We reached out to Sophie's team but didn't hear back. Joe's rep declined to comment.