with the latest beta (and older ones), the following file

%%% start test file

\definefontfamily [mainface] [serif] [DejaVu Serif]
\definefontfamily [mainface] [sans]  [DejaVu Sans]
\definefontfamily [mainface] [mono]  [DejaVu Sans Mono] [feature=none]
\definefontfamily [mainface] [math]  [TeX Gyre Pagella Math][scale=1.12]

\setupbodyfont[mainface]

\starttext
$
\overrightarrow{AB}
\overrightarrow{BA}
\overrightarrow{AC}
\overrightarrow{CA}
\overrightarrow{AD}
\overrightarrow{DA}
\overrightarrow{BC}
\overrightarrow{CB}
\overrightarrow{BD}
\overrightarrow{DB}
\overrightarrow{CD}
\overrightarrow{DC}
$
\stoptext
%%% end test file