Navigation bar buttons not highlighting the way they're supposed to?

i copied this underlining button hover+click style from a free project template and linked them to the corresponding pages in my project. The hover style is correct (shows black line underneath, image 2) but when i click on the page ‘About’, let’s say, the line goes grey (I want it to remain black) and the button ‘Work’ underneath it also has a grey line which I don’t want.

The nav bar is not sticky or fixed to the top (I don’t want to have it fixed) and I’ve selected ‘on all pages’.

Please help!

Hey Randa! Could you please share the url of the live website to be able to debug it better?

Also, if you want we can set up a quick video call to help you with this, it shouldn’t take more than 15 mins

You can send me a message at bill@emunah.design