Text fields in Safari browser not working

Ever since I finally gave in and accepted the software update (I really wish there was an option to just NOT UPDATE, instead of only being able to select "Remind me tomorrow" - my current issue is one of the reasons I prefer to not accept the updates, however, being harassed every single day with a popup demanding that I update gets pretty old pretty fast)..

Text fields in my internet browser (I'm using Safari 11.0.1) have not been working about 50% of the time. I will go to type something in a text field on a website, and nothing will happen; It's as if the keyboard (I'm not using an external keyboard, I am using my MacBook Pro keyboard) has magically stopped working, until I go to use it in literally any other program, and it actually works fine. The only way I have found to get it working, is to repeatedly refresh, click the URL bar, type something in the URL bar, then reselect the text field on the website, until the text field starts working again.

Occasionally instead of a text field on a website not working, it will be the URL bar that doesn't work. In this case, I need to do the same thing to get it working, but instead of clicking the URL bar and typing something then reselecting the text field on the website, I have to repeatedly refresh, click any text field on the website, type something in the text field, then reselect the URL bar, until the URL bar starts working again.

I am currently running MacOS High Sierra 10.13.1 on a MacBook Pro (Retina, 13-inch, Early 2015).