My current Mac Version and current Safari version should be listed below my post. Not?? What ever versions I have of extensions, when I have a problem like this, I always test it by disabling all of them via the Develop Menu. Sometimes it makes a difference and sometimes not.
Okay! Earlier I thought you indicated you did not have the latest version of Safari — you do. Here is something to try that will save you having to use the Develop menu and unlike the Develop menu it will give you pinpoint control.
- Look on the Safari Tool Bar for an icon that looks like a Gearwheel.
- If it is not there, on the Safari menu bar click on View > Customize Tool bar and drag the icon labeled Website preferences to the tool bar then close the Customize Toolbar window
- When you encounter a problem with a website click on the Gearwheel icon (Website Preferences) and UNcheck enable content blockers. That will…
- Disable any content Safari Content blockers or Content blocking extensions — FOR THAT ONE SITE
- Force the page to reload
- Hopefully eliminate any problem using the site
- Safari will remember not to allow any content blockers to be applied to that specific site until you change its setting
- Safari > Preferences > Websites will show you what features can be set and what the settings are for each specific website.