Well, I installed Sequoia on an iMac Pro a couple days ago and experienced significant issues with Safari connecting to web pages. Sometimes it would connect to a page after a minute or more, and other times it would fail to connect and report that there was no Internet connection. I checked a number of Apple fan sites and heard similar complaints. I disabled wifi and voila, my connections were back to quick and stable connections using an ethernet connection to my router.
I gave Apple support a call today and the Apple Specialist began a process of troubleshooting Safari and wifi which quickly ended when she informed me of this:
View attachment 2423827
I'm a bit surprised that this slipped through, but looking forward to the "new update" soon.