Running Google Chrome Version 66.0.3359.139 (Official Build) (64-bit), on Windows 10 (x64).
Chrome has been functioning perfectly fine on my wife's machine until the last day or two when suddenly, whenever she opens a new instance of Chrome, things have been behaving weirdly. Specifically, Chrome opens to her homepage (the default Google page), but all other UI elements are missing; specifically, the top bar (where tabs, user, and the minimize/maximize/close buttons normally are), the address bar (including back, forward, refresh, extensions, and the vertical ... button), and bookmarks bar are all missing. Instead, there's just empty white space up there. Clicking in the white space where those UI elements typically are has no result. I have found that clicking F11 to open to Full Screen mode, and then clicking it again to revert to normal brings these UI elements back, but that'll only last till she closes the window and opens it again.
We've tried Restarting Chrome (killing the task completely), restarting her computer, and verified that she has no pending updates for Chrome (her version is the current most recent official Windows release). We've also performed virus scans to verify that there isn't anything there.
What could be causing this issue, and what steps should be taken to correct the issue? Willing to do a full uninstall/reinstall if necessary, but would prefer to avoid it if possible...