Right-Click Function in Blueprint Error after Play-In-Viewport

After playing a game in viewport and A) hitting Escape while playback is paused by a breakpoint in a blueprint or B) gameplay is stopped via the Quit Game node, right-clicking in an open blueprint will perform a box selection rather than grab and pan the blueprint grid.

Starting the game (via Play-in-viewport) and clicking a few times, then pressing Escape to end the test, has been fixing the issue, resetting the in-blueprint right-click functionality.