Using otf-libertinus with ConTeXt for typesetting math

I’m trying to use Libertinus Serif font for typesetting both text and math.

starttypescript [libertinusserif]
setups[font:fallback:serif]          % security: if not found==> back to defaults
% definefontsynonym[ConTeXt basics name] [Human readable]       [features=default]
  definefontsynonym[Serif]                 [LibertinusSerif-Regular]       [features=default]
  definefontsynonym[SerifItalic]           [LibertinusSerif-Italic]        [features=default]
  definefontsynonym[SerifBold]             [LibertinusSerif-Semiold]           [features=default]
  definefontsynonym[SerifBoldItalic]       [LibertinusSerif-SemiboldItalic]    [features=default]
stoptypescript

starttypescript [libertinusserif]
  definetypeface [libertinusserif]    [rm] [serif] [libertinusserif]    [default]
stoptypescript

setupbodyfont[libertinusserif, 14pt]

starttext
Just some text.

Some text with m{m+a_{th}} in it.

stoptext

and it drops out with the following error:

Math error: parameter Umathsub_shift_downtextstyle is not set


m_syst_action_nop ...artimath #1normalstopimath 
                                                  fi 
l.21 Some text with m{m+a_{th}}
                               in it.

(Note: when I comment out the line with math or do not set the body font, the output is produced.)