Since everything is a budget modular build, they had some funny solutions for making interior walls. Like making frames inside the walls.
I thought of mounting full-length studs between the frames and maybe adding some wood between the frame and the ceiling where there are 15-25mm gaps.
What would you have done if you had such frames inside the walls - torn everything down and rebuilt it the right way, left it as is, or reinforced it...
The goal is, along with several other measures, to try to get them reasonably soundproofed, the fact that the walls can move due to poor fastening doesn't seem like an advantage...
Note, click the image for full size.