Thanks for the report, and sorry for the slow answer here. Confirmed and fixed for the next update. The HUD window used fixed pixel sizes from 100% scaling while its text and spacing scaled with your display, so at 200% the window was clamped and the content overflowed it. The HUD is now laid out from the display's real scale factor (and re-laid out when it moves to a display with a different scale), so it renders correctly at 125%, 150%, 200% and mixed-DPI setups.

Fixed in 5.9.0, now live on Steam and the Microsoft Store. The tuning HUD is laid out from the display's real scale factor, so at 200% the window and its contents match again. If anything still overflows on your setup after updating, a screenshot here would help us finish it off.