The Lohit Devanagari font (both 2.5.1 released and current git) has the nepali_jha_half glyph mapped to 0xfffd. This is an incorrect mapping and should be removed.
This written form is a conjoining form and is not/cannot be encoded, leave alone at this codepoint. Conjoining forms should only be accessible via smartfont tables.
Therefore please remove this mapping. Thanks.
fixed in upstream
Thanks for notifying this.