Check Your Database Connection 
maybe not related in ur case but V17 makes more, smaller SQL queries than V13. If you’re working against a remote database, even a 35ms ping multiplied across many queries adds up significantly https://forum.umbraco.com/t/website-significantly-slower-since-upgrading-from-v13-to-v16/6049?page=2 users are reporting 10–30s including me , save times in this scenario. If possible, use a local DB for development.
but ya try disabling all extensions, the cache settings that might be the case