Zend certified PHP/Magento developer

Font not loading properly with OhMyZsh in Terminal

I have this problem: sometimes OhMyZsh doesn’t correctly load the font in the MacOS Terminal. It happens only sometimes but it’s frustrating. Here is what it should look like:
screenshot

Here is how it sometimes loads:
screenshot

I’ve read online about changing the .zshrc file in the home folder, but there is no option about font, and anyways it loads right sometimes. What could be the problem? Actually I don’t know what information might be helpful, so I will provide them if needed.

Thank you.