Tabs in Safari go blank
MacBook Pro Retina (late 2013)
macOS 10.13.6
Safari 13.1.2
When I link to a new page in Safari I almost always (right-click) open the page in a new tab, particularly when I am doing a web search but other times as well. If the new tab was not what I was looking for or I am finished with it I close that tab. Quite frequently when I close the new tab the first window (the referring page) turns blank. Sometimes the page content reappears after 5 to 10 seconds. Other times it doesn't come back at all. It does not appear to be related to the search engine website because it can happen when linking from many different kinds of web pages. I thought perhaps it was a problem related to older stored data not being identical to the current version of the web page so I searched through my cookies for the ones related to the page(s) I was linking from and deleted them. No change. I've also tried rebooting and deleting history. No change.
What's my next step?
MacBook Pro 15″, macOS 10.13