InDesign variable fonts and anti aliasing

I have been using Acumin Pro OpenType font. I've just tried Acumin VF variable font in InDesign. But the text in the VF version looks blurry and bolder (like the anti aliasing is different / not as good) on screen.

The screen grabs: the first and last lines are Acumin Pro OpenType. The middle line is the variable font.

I've noticed this with other variable fonts. What's going on and how can I improve the look on screen?