I was fast traveling to my settlements to defend them (there were two on the quest prompt: the drive in and Greentop). Successfully defended the drive in. Fast traveled to greentop, successfully defended it. A quest popped up titled "Defending Abernathy Farm" and it directed me to talk to Preston Garvey. Toggled the quest and fast traveled to Prestons location. Talked with him, exchanged some dialogue about failing to defend the settlement. He also mentioned a new settlement needed help, but no new quest appeared. The Abernathy Farm quest wont clear from my Pipboy. Also, it's not allowing me to untoggle the quest, placing a permanent marker on the map/nav HUD.

Any help or work around tips?

I have the same issue but my problem with Sanctuary, also i cant mark that quest. Preston still got functions of companion, i can trade with him, etc.