[Fermé] Old content randomly appearing again on some pages

Background of the issue:
I am trying to understand why some pages on my site suddenly show old content even though I haven’t made any changes. The site is a WordPress multisite installation. I didn’t edit or roll back the page manually, but the old content somehow reappeared. When I check the page revisions, I can restore the latest correct version from there.

Symptoms:
Old content is randomly appearing again on some pages, such as lien caché, even though it had been updated before.

Questions:
Why does old content reappear on my site without manual changes?
Does the WordPress multisite installation affect content updates?