I have installed vim-latex v1.10.0 on Fedora 28, using vim-plug:
Plug 'vim-latex/vim-latex'
I've defined an insert mode abbreviation:
:iab bd text
I can trigger bd
to expand to "text" only with Tab or CR in a line of the type:
rrrrr bd tttttt
in a tex buffer. Neither Space nor punctuation characters work (but they work in an empty buffer). Why?
IMAP
plugin that vim-latex uses to define all its insert-mode expansions. The plugin is quite intrusive and have a tendency to neutralize the usual way to define abbreviations and insert-mode mappings. When vim-latex is present, in (La)TeX buffers, it's better to rely on IMAP to define your own expansions, in a ftplugin.