Questions about RID Rail Racer / Car Robots JRX

Hey guys, I just got the three bullet train set today and while its a lot of fun, I have some issues with it which the instructions dont explain and I hope you guys can help me out.
Firstly, the left foot of the combined form keeps sliding back in. Is there any way to stop that? The foot doesn't recede to block the leg from sliding down, unlike the right foot.



Also, to combine the trains together, the yellow hitch on the white gun wont go back. It doesn't seem the right shape to fold all the way back to form the hitch, is that just on mine?

Lastly, how does he hold his weapons? The individual robots have small fist holes but the combiner hands have this much larger gaps that make it unfeasable to hold the weapons.

Let me know if you can clue me in on any of this, thanks!
Firstly, the left foot of the combined form keeps sliding back in. Is there any way to stop that? The foot doesn't recede to block the leg from sliding down, unlike the right foot.



Also, to combine the trains together, the yellow hitch on the white gun wont go back. It doesn't seem the right shape to fold all the way back to form the hitch, is that just on mine?

Lastly, how does he hold his weapons? The individual robots have small fist holes but the combiner hands have this much larger gaps that make it unfeasable to hold the weapons.

Let me know if you can clue me in on any of this, thanks!