403 Server Error Intermittance tried everything

I have been experiencing an intermittant problem with elementor that I cannot resolved. There are countless posts on this, and I have tried everyting.

When creating a blog post I can create 90% of the time with no issues. Intermittantly when adding a new text block, it stays in grey when I add the text, then I get a 403 server error when trying to save.

If i delete the block it saves.

If I create a new post, copy the content across the same thing happens. I have stripped all formatting in the text editor its just plain text.

Running PHP 7.4, WP 6.2.2

Elementor is up to date.

I have

• Erase some sections
• Increase WP Limit
• Clear post revisions from history
• Devide the work into a few templates
• Confirmed its not a time out, 413 in admin-ajax
• Confirmed to the best of my ability no security plugins/firewall issues

What else can I do – this is driving me insane.