Issues changing hex codes

I'm wondering if anybody is currently experiencing this issue. I had seen a thread from last year below, but I haven't had any luck resolving this issue:

Illustrator CC 2017 switching hex colors

I've been trying to change the hex color and it doesn't stay. Let's say I have a green square. I double click the fill color and enter the new hex color I'd like. I have unchecked the only web colors box. When I click back on it again, the hex code has changed back to what it was.

Anybody have any solutions?

thanks.