Spigot 1.12.1
MH 5.0.9-B464
HolographicDisplays 2.2.6

Essentials/config.yml

currency-symbol: ''

but $ is displayed for Total_Coins (for example). I do not see the amount dropped in the database.

Strange??? I Use Essentials format ...

public String format(double amount) { return mEconomy.format(Misc.round(amount)); }
As you see I dont add the $ to the String............... hmmmm

Yeah, I saw that. Maybe HolographicDisplays does. I think I didn't see it with Holograms, but that has other problems (like lack of persistence).

I tried to change

Essentials/config.yml

currency-symbol: '£'

And it worked on my test server???

I use EssentialsX what do you use?

Sheesh! It doesn't like EMPTY string ''. It works fine with blank string ' '.