See T145717: Performance inspector fatals if opened after saving VisualEditor edit for the original task where this problem was reported.

When saving an edit with VisualEditor, the wgPageParseReport variable is not populated. This is unexpected since that page view should, as much as possible, match how a page view would be after a refresh.

VisualEditor uses the Query, Parse, and Edit APIs behind the scenes. And it uses them to get a list of modules to ensure loaded, as well as mw.config variables to set. And it re-fires relevant mw.hook events.

It seems somewhere along the way wgPageParseReport drops off the radar. Could be an issue in VisualEditor's API module, or in MediaWiki core's API module, or elsewhere in core.