I have a Dell XPS 13 9370 (I think that's the code) and while the scaling has always been a little funky, the latest update to 18.04 really did a number on it. Here's a (hopefully clear) pic of what's going on. Also, it's not just Chrome/PHPStorm, those are just the two best examples, the system Settings window follows Chrome's lead, the Activities and launcher bars are similarly (un)readable to PHPStorm.
With the UI scaling set to 100% (per the settings menu) the UI on Chrome looks good, and the size of the settings menu is fine, but the activities bar is absolutely unreadable it's so small. PHPStorm launches and the text is maybe 1/16th of an inch tall.
So I bump up the scaling to 200%, now the activities bar and launcher look good, PHPStorm looks great, but Chrome and the settings applications are massive! My mouse cursor on some applications is the size of a pin-head and on others it looks correct.
Is there any way I can actually standardize the scaling? To the best of my knowledge none of these apps have any specific settings regarding scaling, so it's not like those are conflicting, and they adjust proportionately to the system scaling setting changing.