URLs inside page code changing

Hello,

There is a strange problem I had two times. Urls inside page code, links (not permalinks or menu links ) are changing to the temp url used in development server. I made no changes to the pages, and no-one else has access. This happens only to some pages not to every page. These are links coded () inside the page code, they are not auto generated from wordpress.

I checked the htaccess and the permalinks settings and everything is correct. Can anyone think how could this happen?

I believe is the hosting provider messing somehow with the website, but they insist they haven’t done anything.

Any ideas?