Magazine Issue?

[PEB]

I have an all matching 1936 S/42 and the toggle will not go into the fully locked position. The magazine does not stay all the way in the gun when inserted ( see pics ) it springs down slightly. I have tried the numbered mag to the gun as well as a Mecgar one. If I push on the bottom the mag while pulling the toggle back it will lock but releases as soon as I remove the pressure from the bottom of the magazine. Anyone have any idea what can be causing this?

Any help is greatly appreciated!!!