many of my image links are broken

I recently stopped using Stackpath CDN, as my new web host has its own CDN.

However, many of my images still have ‘stackpathcdn’ in the filepath:
https://p7y9z4c4.stackpathcdn.com/wp-content/uploads/2018/05/serp-snippet-01.png

The result is my website is littered with broken images. I’ve just spent an hour on Live Chat with a Stackpath agent trying to solve the problem, but nothing we tried worked.

All I need to do is replace ‘stackpathcdn’ with my own root domain:

In other words, this:
https://robpowellbizblog.com/wp-content/uploads/2018/05/serp-snippet-01.png

instead of this:
https://p7y9z4c4.stackpathcdn.com/wp-content/uploads/2018/05/serp-snippet-01.png

Does anyone know of a WP plugin that will do that?

Thanks,

Rob

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