AI controller character using not shortest path

Hello, I have a question why does Pawn using “AI MoveTo” command using not optimal path in some cases? On this case you can see that NPC uses straight path, everythig is ok.

But when moving back from the big building to the smell NPC uses not the same optimal path, but moving a bit to a middle of the map and then makes a little turn?
Why is this happening? I didn’t change enything between moves.

Thanks for help!