What I see is that SecTrustEvaluateIfNecessary is causing this. Which means a deadlock to my understanding: unless you figure out how to override certificate trust check of WKWebView to do it in background thread separately from loading web view url (needs to be on main thread).

same issue here, although i went quite far to clear up the web view, and delegates and attached config after done with web view, still its kept in memory.