Tooltip and other text is too tiny on high resolution displays

I have a Dell Precision 5510 laptop, running Windows 10. This has about a 300 dpi screen resolution. I am a user, not a developer of Qt. I am using the Perforce Helix P4V windows app, and find it nearly unusable on this platform. I have contacted the developer to report a bug, and he claims that it is a Qt bug. The problem is that the UI text (column headers, tooltips, ...) is tiny, about 0.5 mm high. Also it is difficult to determine the direction of the arrow icon in the merge/integrate window because it is so tiny (is this a glyph or an icon?). I am unsure of the actual Qt version used in this app. If this has been handled, please notify the developer. But since I have not seen any resolution-related bugs in the bug list, I suspect that this is not a known issue.