Safari 15.4 on Monterey 12.3 cannot access certain websites

I gave up on Safari 15.4 weeks ago after years of use. After upgrading to Monterey it was horribly slow on start up, and shut down....always got the spinning ball. Websites seemed to take forever to load....or start to load and then freeze for 5-10 seconds before continuing to load.

Cleared cache, history, removed all extensions, cleared some of plists (as suggested by others) and it did nothing to change the problems. I switched to Firefox and it starts fast, loads fast and does not block anything. No lag on website loads.

Using a 2017 iMac 2.3ghz dual core i5, with Monterey 12.3.1, and 16gb of memory.

Just for grins, I tried Safari again today...took almost 30 seconds to load, and there was no change in the lousy performance, and when shut down, the spinning ball went for another 20-30 seconds before it quit.

Until Apple corrects something that is apparently wrong I won't be using Safari. I think their support for desktops are waning since doing any kind of search on Safari 15.4 usually shows a slow of stuff for pads and phones but very little for desktops.

My wife's iMac desktop, I hardly ever fool with since she uses it strictly for her business. It is a 2016 iMac with a 2.3ghz dual core i5 but because of the age is stuck on Catalina for the OS. I fired up Safari on it yesterday (also 15.4) and did not experience any of the glitches on like mine running Monterey. After clicking icon, immediately filled screen. No lag, stutter or stall on ANY website. And when shutting down, immediately quit. So what is making such a drastic difference between performance between 2 machines, several years apart, with basically same hardware, making Safari run so amok on the Monterey OS but not Catalina????

Rich in Space -> I don't use anything related to iCloud. I have everything pertaining to iCloud turned off.

I do all back ups on my own backup security system (double redundancy) and don't need to have my documents and other information on some other server outside my network.

Try this url https://www.abc.net.au

What you have described seems to happen with some users of Safari. So far the reason seems to be unknown. The easy solution is to use another browser for problematic sites as you have done.

Many of these problems are probably connected to the iCloud Private Relay function. Try switching it off for the sites in question.

iCloud Private Relay

Then it’s not iCloud Private Relay.