Can’t update homepage

Having a weird issue with the homepage of the above site. Hoping someone can help.
If I make a change to any element, text or image, I can’t update the page. I get an error that’s there’s an issue with the database.
Now, this is the only page/post on the site that has this issue.
And by a process of elimination – disabled all plugins, changed the theme, the issue seems to be the column block at the bottom of the page.
If I remove that block, I don’t get an error and I can update the page.
However, I’d like to keep the block (I’m guessing the issue is the icons and not the blocks per se).
Anyone else has this issue?
Any ideas on how I can resolve it?

And yes, the first thing I did was to make sure I didn’t have any REST API issues…

The page I need help with: [log in to see the link]