Here's one that has me stumped: external links in email messages, in software windows, etc. take about 30 seconds to cold start my browser and / or open a new tab if the browser is open. 
Fresh Windows 10 install (post October Creators' Update). 
16 GB memory - i5-8400 CPU - fast system.  
Chrome installed as default browser. 
Same slow behavior with Internet Explorer when it is selected as default.
When a link is clicked in an Outlook message (Office 365), a "program working dot chase" can be seen at the very top of the message, under the ribbon.  
(Tweaking util installed after this behavior was detected - speed tweaks applied; no change.) 
Any ideas?
Thanks.