Links stopped working on most pages

The ones that do not work seem to have a manual id set in Gutenberg with an older (?) Id. Please check if you (or an old plug-in) set these ids of the headline block and remove these ids in the Gutenberg Editor.

I’m so sorry I have no idea what you mean ???♀? I didn’t change the headings, if that’s the case?
I have simpleToC added as a reusable block to all posts.
I removed the reusable block from one post and added just as a stand alone block, and it worked.
Then I went to the edit reusable blocks, and refreshed the simpleToC that was there (on the refresh button on the block options), saved and it didn’t make a difference.
I then ungrouped the simpleToC block in the reusable from the paragraph block that says Table of Contents, and inserted a fresh ToC block, regruped and saved.
It didn’t work.
So from these I suppose I’d have to open all my posts and insert the block individually to work? Or is there a way to make the reusable work again?
I understand that I’m a hard person to help, I’m sorry…

No that should work. You can use SimpleTOC as a reusable block. Please check what happens if you delete the heading blocks that do not work and add them
Again. If it works then someone or something altered your heading blocks.
Some plugins do that.

To make this more clear: I think another plug-in changed the ids of your headings. SimpleTOC I not the culprit here.

I understand perfectly that it’s not a SimpleTOC problem, and I appreciate a lot that you tried to assist me.
I tried a couple more things to solve the problem: I opened a post, removed the reusable SimpleTOC, deleted and re-created all the headings, and again added the block. It didn’t work, it pulled the same old headings. I cleared the cache. I also installed another similar block TOC plugin, and the same thing happened.
Even when adding just a stand alone block it’s not working, even after re-writing all the headings.
For now, I removed the ToC all together. It’s unfortunate, but I can’t see how to work around this. The only different thing on the site (from when TOC was working) is cloudfare, and the ad network (not on plugin, but through cloudfare). And these I cannot be without.
Again, your help was much appreciated and I know it’s not a problem with Simple TOC. It’s a very nice, light plugin, and I’m extremely picky with what I install. Thank you.

I’m also experiencing the same problem on my website. I noticed this issue today on 5/23/22. SimpleTOC links were working normally last week, not sure exactly when things changed.

What’s happening has something to do with Gutenberg’s group block. SimpleTOC links will not work if a heading is within a group block/is grouped with other blocks.

I’ll start a new thread for this.

This is another problem since the ids of the headlines are different. In your case, charliexoxo, the ids are missing when the headlines are in a group