How do I stop npc going backwards?

In my testing game, I have distance-based node pathfinding, and it works. Except for the fact the the npc will go backwards.

What it’s doing:

What I want:

How would I make sure the part is not behind the npc’s LookVector?

just save the last node the npc was at to a variable and when searching for a new available node check if the new node is not the last one

I already have that, the npc can still go backwards even with that