This issue has been there since I began using FF and it’s in smed too.
Some glyphnames keep changing between correct and wrong according to AGL spec and AGLFN. I’ve set all my Fontforges and smeds to use AGLFN. However, some glyph names keep changing every now and then (it’s unpredictable when and which), changing file names in the sfdir too. You can see this in my latest commit to EBG: georgd/EB-Garamond@273c368
Glyphnames that keep changing in my fonts (the first ones are correct):
uni01DD/uni01dd (only uppercase hexadecimals are allowed)
Parallel bug report for smed: https://bitbucket.org/sortsmill/sortsmill-tools/issue/26/glyphnames-keep-changing
@georgd is this now fixed?
Yes, this is fixed. I close this.