I installed the WP Downgrade plugin to take one of my sites back to 4.9.9 (I never upgraded the others). I will continue using this version on all my sites until the forked WordPress (known as ClassicPress) releases their first fully stable and working version.

I really believe moving Gutenberg to core at this point was a huge mistake. Folks over at WP don't appear to understand that or are in denial. Gutenberg should have remained a plugin. I don't understand the rush to get it into core.