Left-clicking (or searching) a POI should not clear the existing route's blue itinerary line from the map view
With version 46 beta's vector tiles, if you select a point (whether by clicking on the map, or by clicking on a search result), any blue transit/directions routing line will get cleared from the map, even though the route itself is not cleared (thankfully), as evidenced by the sidebar.
GNOME_Maps_46_beta_routing_itinerary_blue_line_gets_cleared_on_POI_selection
It should maintain the blue line.
Edited by Jeff Fortin