Sorry to hear you’re experiencing trouble with this.
Unfortunately I haven’t been able to reproduce your issue on my end.
There might be a CSS error which could be preventing your stylesheet from being loaded on the frontend.
Could you possibly use this CSS checker, to ensure that the CSS you’re using is valid?
Sorry!
It was my problem. I figured it out when I had a further investigation. I forgot I had added the same custom code using the WPCodeBox plugin. That code was inheriting the styling in the stylesheet.