Interpolation Issues - Italic .glyphs file 2021-10-14

[kenmcd]

File: Merriweather-Italic.glyphs downloaded today (2021-10-14)
Found 69 glyphs which appear to have some interpolation issues.
Some are different start point issues.
Some are different element order issues.
Some diacritics moving oddly appear to be advance width issues.
The glyph names are listed below.
Here is an animated GIF of the glyphs:

Glyph Names

AE
AEacute
K
Kcaron
Kcommaaccent
L
LJ
Lacute
Lcaron
Lcommaaccent
Ldot
Ldotbelow
Lj
Llinebelow
Ohungarumlaut
Uhungarumlaut
tdieresis
ae.sc
aeacute.sc
f.sc
fdotaccent.sc
l.sc
lacute.sc
lcaron.sc
lcommaaccent.sc
ldot.sc
ldotbelow.sc
llinebelow.sc
lslash.sc
m.sc
macute.sc
mdotaccent.sc
mdotbelow.sc
y.sc
yacute.sc
ycircumflex.sc
ydieresis.sc
ydotaccent.sc
ydotbelow.sc
ygrave.sc
yhookabove.sc
ymacron.sc
ytilde.sc
Fita-cy
Ghestroke-cy
Aie-cy
Obarreddieresis-cy
Edieresis-cy
Uhungarumlaut-cy
nje-cy
fita-cy
kaverticalstroke-cy
udieresis-cy
iishort-cy.sc
iigrave-cy.sc
kje-cy.sc
em-cy.sc
ha-cy.sc
hadescender-cy.sc
emtail-cy.sc
aie-cy.sc
ghestroke-cy.loclBSH.sc
mu.sc
lessequal
slashlongcomb
hungarumlautcomb.case
ustrait-cy.sc
ustraitstroke-cy.sc
dieresiscomb-cy.case

[davelab6]

@kenmcd hmm I see you using FLAB7, not GlyphsApp; maybe that was mis-reading the .glyphs data?

[kenmcd]

@kenmcd hmm I see you using FLAB7, not GlyphsApp; maybe that was mis-reading the .glyphs data?

I don't think so.
For example the issue with the Æ appears to be a different start point in the ItalicBlackWide master.
To double-check I opened the actual variable font (Merriweather-Italic[opsz,wdth,wght].ttf) in FontCreator and Samsa.
In both I see the same issue as in FontLab with the .glyphs source file.

Here is FontCreator with the variable font:

Here is Samsa with the variable font:

This is the same as what I see in FontLab.
Perhaps you can take a look at this character in GlyphsApp to confirm.

[davelab6]

Oh! Sorry for doubting :) Sorry to skim this - to me, they are "interpolatable" but don't interpolate correctly!! XD