MathCAD Prime 4.0 Title Bar expands into workspace

Hello,

I find that the title bar of my MathCAD Prime 4.0 slowly expands into my work space, making the available space to write smaller. It doesn't seem to be something that I can click and drag back to it's normal position. Eventually, I am forced to close, and reopen my worksheet to get the full-sized work space. This seems to be the only way that I know how to deal with it. If anyone has experienced this, or has a solution to the issue, please let me know. I've attached a screenshot of what my worksheet looks like while the problem is present.

Much appreciated