Error when pressing Shift+F10 with a feature focused

[prushforth]

          Just an error I noticed that is on main also, 

• Go to this page, and open the console https://maps4html.org/experiments/screenreader/restaurants/
• tab to the first feature
• press shift+f10
  The following error is displayed
  

Originally posted by @AliyanH in #844 (comment)