regex snippets jump to wrong placeholder

[ucasyfp]

I defined three snippets,

snippet "([a-zA-Z])bar" "bar" riA
\overline{`!p snip.rv=match.group(1)`}$0
endsnippet

snippet // "Fraction" iA
\\frac{$1}{$2}$0
endsnippet

snippet mk "Math" wA
$${1}$$0
endsnippet

Then when I typed as follows,mk,//,abar, I get

Then I typed tab to jump to the next placeholder, which should be in {}, but in fact it jumps to the end of the line

[ucasyfp]

It seems a bug of latest version of coc.nvim.