It's a weird edge case with gloomhaven's line of sight rules.

Wait wait wait wait. Touching a corner counts as touching a wall?! Are you serious? So if your line of sight line touches any part of the edge of a wall tile, then they don't have line of sight?

I don’t understand why there is no line of sight. You need to be able to draw a line from any point on the monster hex to any point on the character hex, which is possible from a number of places.

Thanks everyone! I've tried and, as pointed out, it had to do with LOS and the hexes being surrounded by walls.

To be clear, the only hex with an issue in this example is the players. All six corners are touching walls

Maybe the lack of line of sight?

I think this is why... It is one on the weird cases where GH's RAW line of sight does funny things...

There is nowhere that any monster can get line of sight to the character. Because of that, neither monster will move.

Noob question here... what is this app being shown?

https://gloom.aluminumangel.org

Its a weird situation but I've tested several variations.