Why the low FPS on mobile?

Thast just it. Textures are max 256x256 And that is just 1. The rest are 128x128 and below. I have no shadows. I have 1 light that does not cast shadows. I have fully rough materials. ShaderComplexity displays everything green. As in there is no shader complexity. I have no normal maps.
Nothing.

Its as run down as it can get. Apart from removing 1 light and setting it to LDR.

Compared to the other game which has Normal maps, specularity, Dynamic shadows, Vegetation, particle effects etc.
Something is amiss.

I have optimized games in the past using UE4. And they run fine. The only thing different is that this game constantly deletes and spawns new cars and actors.
Which i fail to think would cause such a massive slowdown.

If i completely remove UMG i already get a frame increase of 10fps.