Browser flashes previously closed icognito tabs when switching between currently open tabs

MacBook Pro mid 2015

iOS 10.13.6

Chrome (Version 68.0.3440.106 (Official Build) (64-bit))

Had two Chrome browser windows open, both with multiple tabs open, one window was incognito. Closed the incognito window. When I went back to the non-incognito browser window and switched between tabs, a flash (like, a quarter of a second) image of one of the now-closed incognito tabs would appear on the screen. Never have seen this before.

In a thread that has been discontinued (below) there were comments that this happened when switching between apps AND when switching between tabs in a Safari browser window for some users. Many were using iPads. I noticed a few comments about the Notes app for some of those who have experienced the problem. I rarely have the Notes app open, but I did today, which is the first time I have experienced this. Perhaps there's something that happens because the Notes app is open.

Problem identified in thread here, too: Safari iOS 7 keeps flashing previously closed tabs upon reopen? Security Problem