Some TeX snippets don't expand according to config about vim-snippets HOT 2 OPEN

For what is worth, I agree: the \bf syntax is awkward and it is not correct, a workaround might be to switch \bf and the opening brace as follows: {\bf ${1:${VISUAL}}}. All in all, personally, I do prefer \textbf{}. In fact, a quick search through the history shows that it used to be implemented version until a couple of months ago, commit ddcda4f; notice that since then, more recent commits reverted some changes applied by the former. Actually, the original snippets are still presents in snippets/tex.snippets, however they are overridden by those in UltiSnips (if you are using UltiSnips, I guess).

Notice also that similar problems hold for snippets it, rm, un

from vim-snippets.

if you not set like this

vim.g.UltiSnipsSnippetDirectories = {
  vim.fn.stdpath("data") .. "/site/pack/packer/opt/vim-snippets/UltiSnips/"
}

in default, this ultisnip plugin load this snippets/ directory, not the Ultisnips/ directory, this will not be overwritten by Ultisnips/ directory @angelus2014

from vim-snippets.