Different Browsers, Different Strokes

I use Chrome as my default browser. There seems to be some setting(s) which inhibit accessing certain urls/sites. In some cases when I click on a url the page will start to load a bit, showing maybe a geometric figure, but no content loads.  In other cases there's no activity. 

Possibly connected, sometimes I get a message about the site not being secure--i.e., not using https.  Some of the time I can understand; it's an small website, likely not regularly updated, but some of the time it's idiosyncratic, a site which I can access some of the time, or almost all the time.

Today I tried to access a wikipedia website, which froze.  So I switched to Firefox and had no problem.  

When I look at the settings in Chrome, I don't see anything which is likely the cause.