Open /xrc/XF/PageCache.php, backup a copy to your local computer.
For xf 2.3 :
Find this function : generateCacheId(), within that function :
Find this line : $cacheId = 'page_' . sha1($uri) . '_' . strlen($uri) . "_s{$styleId}_sv{$styleVariation}_l{$languageId}_c{$cookieConsentId}_v" ...