The issue has been fixed in the latest release of InDesign – InDesign 2021. The fix was also available in the previous version of InDesign – version 15.1.2
Please update to either of these versions of InDesign to get the fix.
Adobe InDesign team
An error occurred while saving the commentSabina commented
The spacing doesn't increase with size for the variable fonts. I'm currently using 15.1.1 version and If you check spacing for Source Sans VAR from ExtraLight to Black letters will start colliding. Please take this issue into account for next update