Brush Roundness changes when switching presets in Photoshop Beta

I'm using the latest version of Photoshop Beta. Whenever I right-click on the canvas to open the brush picker and select a different brush, the Brush Roundness automatically changes to 0%.

I have to manually set it back to 100% every time. Is there a setting that controls this, or could this be a bug in Photoshop Beta?

I do a lot of photo compositing, so this becomes quite annoying and time-consuming. I also don't want to reinstall Photoshop since I have several custom brushes and other settings installed that I'd prefer not to lose.