lfilho
commented
7 years ago More research:
https://www.reddit.com/r/neovim/comments/4st4i6/making_ultisnips_and_deoplete_work_together_nicely/
https://github.com/Shougo/deoplete.nvim/issues/470
https://github.com/Shougo/neosnippet.vim/issues/365
Seems like that UltiSnips have some bugs with neovim still (as of this date). Maybe neosnippet (also from Shougo) will be better but he said he's working on an even better one, specific for nvim: https://github.com/Shougo/deoppet.nvim
Seems like the deoplete supports UltiSnips snippets in its completion... So might worth the change https://github.com/SirVer/ultisnips