Possible that you installed other fonts that can conflict with ttf-nerd-fonts-symbols-2048-em?
Edit: also mentioned on this post but it is subtle. Shrunk icons on panel bar - #4 by joekamprad
Edit 2: try reinstalling ttf-nerd-fonts-symbols-2048-em and also search what package you have with nerd in there and post the output back here. For example pacman -Qs nerd
.
for example I have:
$ pacman -Qs nerd
local/ttf-nerd-fonts-symbols-2048-em 2.2.2-3
High number of extra glyphs from popular 'iconic fonts' (2048-em)
local/ttf-nerd-fonts-symbols-common 2.2.2-3
High number of extra glyphs from popular 'iconic fonts'