Hi there,
Thank you for getting in touch, we do appreciate your time.
We’ve recently received a few reports of this issue and after looking into this in more depth it appears Google Maps has changed the way they handle/load map themes. As a result, some users are experiencing issues with the default map theme, which prevents the markers from loading fully.
We’ve released an update which fixes the issues with the default theme, however, it will need to be resaved in order for your map to be restored. Please update your Basic plugin version to 9.0.19. Once complete, please navigate to Maps > Edit (your map) > Themes > Select the first theme from the Theme Presets panel > And Save your map. Once complete, your map should become fully functional once again.
I hope this helps?
Kindest Regards,
Matthew