Safari broken after sofware update to 17.5

After updating Safari to version 17.5 on a 2015 iMac running Monterey 12.7.5 pages do not load correctly, Safari quits unexpectedly, audio in YouTube changes to full volume unexpectedly, and Google and YouTube need to be re-signed in on change of tabs. Emptying cache and restarting Safari and macOS does not fix the problems. All updates are current and macOS starts normally.