ok I did something dumb!
added regenerate thumbnails plugin to the site as it was being suggested to speed up the website which is also directly connected to my APP.
After adding it the website no longer displays full-size on the browser page.
I’ve tried looking for a solution but seemed to be pushed in the direction of reloading a saved version sadly my last back up didn’t include the update to the PHP so will not load without me taking the settings backwards.
I’m hoping you have come across this problem before and know the fix.
Here’s hoping
Thanks
Derek