Light Blue/Purple Keys for text fields - dark mode

Hi there,

Seen some posts in the past but with no resolutions - my keyboard (and many others but the looks of ‘me too’ comments) has light blue/teal buttons for the Shift, Backspace and return keys when in dark mode. This doesn’t exist in light mode, and strangely the ‘123’ key isn’t the same matching colour (like it is in light mode). Have tried clearing Safari cache & browsing data, and force closing safari. Only seems to occur in Safari, and when using a text field in a web page (i.e. not when editing url’s).