When the active caret is in a WPRichText and I change VCL styles, the caret disappears but is still in the WPRichText because I can type but there is no caret until I move focus away and come back to the WPRichText. Note that the caret does not disappear if in a TEdit component for example, just a WPRichText from what I can tell.
WPRichText 9.2.000
Delphi 10.4.1