I cannot see highlighted text

When I drag the mouse across an area of text to add URL link or to delete there is no background color showing me which text has been highlighted. Applies to any block in which I use text

I have cleared cache on website and browser, tried different browser, uninstalled and reinstalled plugins – Kadence blocks and UAG, no change

I use the Astra theme

The page I need help with: [log in to see the link]