Many Setup pages not rendering in Lightning

Since starting last week many Setup pages are not rendering completely in LEX

• Problem occurs in Chrome (my preferred browser).
• Does not occur in MS Edge.
• Reproducible in all SF Orgs while using LEX.
• Not reproducible on older computer.
• It appears to be issue with Setup content displayed in iFrame; classic setup pages displayed in LEX.
• I have been searching all over google to find a remedy, but no luck.
• Is this a Chrome setting that can be fixed?