Formula does render on HTML output, but not in Plurimath.org

[manuelfuenmayor]

Following formula:

[stem]
++++
{:(ii(E)_1, =, ii(A)_1 cos[ii(varphi)_1]),(ii(E)_2, =, ii(A)_2 cos[ii(varphi)_2]):}}  rarr I = langle (ii(E)_1 + ii(E)_2)^2 rangle_t = {ii(A)_1^2}/2 + {ii(A)_2^2}/2 + ii(A)_1 ii(A)_2 cos[ii(varphi)_1 - ii(varphi)_2]
++++

renders on HTML output, when compiling mep-metre-definition-en.adoc:

(The MathML code is a little large, so I leave it as text file: complex-formula.txt)

But when I test it on plurimath.org, it doesn't render. And it fails the GitHub test; see comment: metanorma/bipm-si-brochure#257 (comment).

Tested on plurimath 0.8.18.