Hi, list

\startMPpage
draw outlinetext.d("\mathematics{\sqrt{2}-1}")(withcolor black withpen
  currentpen) scaled 1;

\stopMPpage

fails (radicals are not drawn at all). As for context --version,

mtx-context     | ConTeXt Process Management 1.06
mtx-context     |
mtx-context     | main context file: /usr/local/context/tex/texmf-context/tex/context/base/mkiv/context.mkiv
mtx-context     | current version: 2024.04.01 08:59
mtx-context     | main context file: /usr/local/context/tex/texmf-context/tex/context/base/mkxl/context.mkxl
mtx-context     | current version: 2024.04.01 08:59

Maybe it's only me, but I tried with several fonts and the outcome is similar.

Best regards,

Jairo