Using parentheses after insert mode abbreviations will not trigger the abbreviation

[againxx]

I set iabbrev pritn print in my vimrc, but the abbreviation didn't expand after I typed pritn(.

In Learn Vimscript the Hard Way, the author says that

Vim will substitute an abbreviation when you type any "non-keyword character" after an abbreviation.

Other non-keyword characters work fine, such as ,. Like the discussion in https://vi.stackexchange.com/questions/10649/expand-abbreviation-when-the-following-non-keyword-character-is-mapped-to-someth, the problem seems to lay in the mapping.

[chemzqm]

Don't know how to fix.

[AeolusLau]

Got the same problem...

@chemzqm Is it possible and acceptable to always trigger a CTRL-] before coc-pairs handle its key characters?

[chemzqm]

Tried to feed CTRL-], but not work.

[AeolusLau]

Sad...