OK, now we are getting somewhere, I finally disabled All-in-one SEO because I saw how much resource it took looking at Query Monitor. I noticed that both Monster Insights and SEO All-in-one were putting up Headline suggestions, so I tried that in the quest to keep reducing, and suddenly things are under control. I hope that was the issue. I’ll start adding things back now. It is so hard to know what conflicts with what with WordPress, but this makes some sense since they are competitive products.
So now I need to check by adding back in Boost connection to Tumblr and the many ActivityPub and Mastodon plugins, but wish me luck!