Consider the phrase specific floating office, which includes ligatures for fi, fl, and ffi.
https://fonts.google.com/specimen/Hind?preview.text=specific%20floating%20office&preview.text_type=custom

The spacing after all these ligatures looks good for light weights. The spacing after the ligatures for fi and fl also looks good for heavy weights. However, the spacing after the ligature for ffi gets increasingly worse (by being too big) as the weight increases.
Consider the phrase

specific floating office, which includes ligatures forfi,fl, andffi.https://fonts.google.com/specimen/Hind?preview.text=specific%20floating%20office&preview.text_type=custom
The spacing after all these ligatures looks good for light weights. The spacing after the ligatures for
fiandflalso looks good for heavy weights. However, the spacing after the ligature forffigets increasingly worse (by being too big) as the weight increases.