Furniture parting company.

I have a 2012 A/S Worcester. We are away for three weeks and have noticed that some of the cupboards have parted company with the side walls. This is most evident in the wash room where the toilet joins the side wall. There is a gap big enough to poke my finger into it. I have tried tightening the screws up but to no evail. Has anyone else experienced this happening? I am wondering if the furniture has shrunk due to the warm weather. Obviously when travelling there is a lot of movement. Thank you in advance for your replies.