Additional CSS H1 font sizes not displaying

Hello, Regarding: Appearance/Customize/Additional CSS I was making small adjustments to site font styles and then suddenly I was no longer able to view changes in editor. See for yourself go to taxresidents.com check it on mobile, tablet and then desktop. Desktop seems to display somewhat correct, but still I cannot see changes in editor, like if I change body h1{ font-size: 20px important;} to 1px, it does not change. Also, mobile and tablet are stuck at small h1 sizes which are not proportional. Other elements seem to work such as if I adjust line-height et cetera but not font-size or font-weight. What is causing this? It just seemed to happen all at once while I was making simple adjustments which I have done many many times before. Then it just showed incorrect font size and no matter what I did it would not rectify. It just seems frozen, I have cleared cache on cloudflare, and WP, browser et cetera but this does not resolve the issue. Can you assist please? Edwin