TYPO3 has several caches:
some tables in the database
a lot of files at typo3temp/Cache
Sometimes occures a cache confusion, the cache isn't up to date and affects bugs.
Please clear the cache in every case of a bug.
Click on all available thunderbold-icons in the backend.
Please remove all files and directories from
typo3temp/Cache (TYPO3 6.2, 7.6)
typo3temp/var/Cache (TYPO3 8.7)
But don't remove the folder Cache!