The world-ready paragraph composer (InDesign CC 2019) applies the DFLT's "kern" feature on top of Deva's "dist" feature, which leads to double-kerning if both features point to the same lookups. It should only apply the features registered for the script.
1. Install the attached font, a modification of Noto Devanagari. Note that in this font, Deva only has "dist" registered, not "kern". DFLT has "kern" registered.
2. Make a text box with the content "च्ज"
3. Set paragraph language to "Hindi", select world-ready paragraph composer
4. Set paragraph font to "TEST FONT DEVANAGARI KERNING"
Expected output: correct.png
Actual output: wrong.png. This looks subtle, but depending on the design and kern direction can create gaps in the hanging baseline.
The problem can be worked around by unregistering the "kern" feature for DFLT. Another workaround is setting kerning to "0" manually in the paragraph properties.