Vim doesn't display my echo if it's 2 characters

Question

On Vim 9 linux running this code:

inoremap <C-n> <C-o>:echo "aa"<CR>

doesn't display anything whereas:

inoremap <C-n> <C-o>:echo "aaaa"<CR>

displays "aaaa" and Press ENTER or type command to continue as expected

Answer 1

I believe the result of echo is overridden by the INSERT status. I propose to set cmdheight to 2.

set cmdheight=2

To validate the hypothesis you can try to replace echo by echom and verify if a message has been output using :messages command.

Not exactly related but for command mapping in insert mode or visual mode I suggest <cmd> modifier:

inoremap <c-n> <cmd>echo "aaaa"<CR>

No need of <C-o> no need of <C-u> and no need of : among other things.