Insert from URL link not updating

Hi

I add an image to a page by using the insert from URL method and this works fine. Next day I update the image that I link to (which is an updated temperature graph that I update on a daily basis) on my own personal website but the updated image does not update in the page in the link I’ve inserted even though you can see it clearly if you put the URL into a browser.

Am I missing something here?
This method of updating worked very well to just recently. I have swapped web hosts in the meantime though from HostPapa to Freshfields which might have something to do with it.

Any help would be appreciated.

Bruce.