In Apify/Crawlee 2.x, a CheerioCrawler configured with a SessionPool (e.g. for proxy rotation) and persistCookiesPerSession: false overwrites manually set request cookies. In 0.2.x, setting persistCookiesPerSession: false let you manage cookies yourself while still using the session pool. A change in _requestFunction() means only useSessionPool is checked, so the flag is ignored and the crawler's cookies win. The result is that manual cookie headers set on requests get silently replaced.