Safari Malfunctions

Mac Mini (Late 2012) High Sierra 10.13.6 Functions well in general - however, in Safari, certain web functions won't work. I can not access/edit contact info in my Google Account. Yahoo works fine. Also certain websites - USPS etc - will not allow me to do account related business. If I open Chrome these all work fine, so I suspect it is a Safari issue. I realize it's an old OS, but haven't updated to Monterey because most stuff has worked fine so far. All these tasks/accounts perform fine in Safari on my iPad. I have cleared the cache and cookies on the Mac Mini.