Show on map feature for saved destinations not working properly

🚧 THIS IS A TICKET MIGRATED FROM UPVOTY. The original ticket and comments will be available for a limited time over at:
https://abrp.upvoty.com/b/report-a-bug/show-on-map-feature-for-saved-destinations-not-working-properly/
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1. Show on Map feature is activated in the edit screen for saved destinations. But markers are only shown briefly when scrolling/zooming-in/out over the map. when stop scrolling//zooming-in/out, the markers disappear.
2. When saving a destinations via the heart symbol, the symbol does not stay illuminated/colored after clicking/saving. new feature?