To Reproduce

1. Install wordpress in a path containing a char that is part of the regular expression syntax. Example: install at /releases/2024-09-02T11:32:23+0000/ so the cache folder will be at /releases/2024-09-02T11:32:23+0000/wp-content/cache/wp-rocket/
2. Purge the cache via the admin bar ( or other method)
3. The cache is not purged

Why it happens

the function rocket_clean_files uses the function _rocket_get_cache_dirs at

_rocket_get_cache_dirs searches the folders by regex:

But _rocket_normalize_path( $cache_path, true ) only escapes the slash but not other characters.

It should be replaced by preg_quote( $cache_path, '/' )