If you load the Plex typescript, a spurious space is added on the first switch to another font, messing up any alignment. This doesn't happen with any other fonts; only with Plex. MWE: \setuphead[section][style={\switchtobodyfont[modern]}] \setupbodyfont[plex] \starttext \section{A} A \stoptext I was able to fix this by removing the space immediately before the "%" on line 136 of "type-imp-plex.mkiv", changing it from this (original): \definefontfeature[plexwideneddefault][default][extend=\luaexpr{1/0.85}] % An odd floating point number to correct monospace. to this (fixed): \definefontfeature[plexwideneddefault][default][extend=\luaexpr{1/0.85}]% An odd floating point number to correct monospace. I'm pretty sure that TeX is ignoring spaces at this point, so I have no idea why this issue exists or why the fix works. -- Max