Properties Panel Sluggishness, Reset Issues, and Dropdown Scrolling

Hi ​@Theresa Rostek ,

I did some more testing, and the slider reset issue appears to be a UI synchronization problem rather than the reset itself failing.

• How are you resetting sliders?
  I tested both double-clicking the slider and using the reset/back-arrow button. In both cases, the parameter itself is reset correctly, but the UI fails to update visually. For example, if Contrast is at 50 and I reset it, the actual value becomes 0, but both the slider and value remains visually positioned at 50.
• What is happening?
  The first reset generally works correctly. However, after interacting with the same slider multiple times, the issue starts occurring. The reset is still applied internally, but the slider does not update to reflect the new value. UI is still at its previous value when it has actually already been reset.

• Is this happening to all Color parameters or specific ones?
  I initially noticed it with Color parameters, but it does not appear to be limited to Color sliders. I have also reproduced similar UI update issues in Audio slider.

  The Crop section is also affected by the reset/update issue, despite not having sliders. Using the reset/back-arrow button there can similarly result in the displayed values not updating correctly.

• Is this happening to sliders only?
  No. There also seems to be a broader responsiveness issue with the Properties panel.

  For example, when selecting the Crop or Transform category in the Video section, the blue selection outline can take at least ~700 ms to appear. The delay is very noticeable and makes the panel feel unresponsive. also Crop values has this reset issue as i said earlier. (Transform parameters update fine though.)

I haven't tested this extensively with effects yet, but I would expect to see whether the same behavior occurs there as well.

Overall, this is not isolated to the Color sliders. The common issue seems to be that the underlying action occurs, but the Properties panel UI is delayed or fails to synchronize its visual state with the actual parameter state. The panel also feels generally sluggish when switching between categories.