weird behaviour with string.gsub

[nxmxsxs]

https://github.com/MurdeRM3L0DY/dotfiles/blob/b363ce6ac6dc8e8ddb5c115f149d9c1851b53b4d/roles/nvim/files/lua/plugins/heirline/config.lua#L487

Hello, I've encountered this weird behaviour with gsub where it works when I'm in certain directories but doesn't for others. Do you have any idea what I could be doing wrong?

[nxmxsxs]

Here's a workaround I'm using:

      {
        provider = function(self)
          if str_find(self.stlbufname, self.stlcwd, 1, true) then
            return str_sub(self.stlbufname, #self.stlcwd + 1, -1)
          end

          if self.stlbufname ~= '' then
            return fnamemodify(self.stlbufname, ':~')
          end
        end,
      },