Derya TM22 mag issue

[u/Solariss35]

I just got a TM22 with 12" barrel, came with a 10 rd mag that feeds perfectly.

I bought a couple of the Derya 15rd mags, but it doesnt insert well at all. On inspection, there is a difference in the rear notch of the mags. Is this an issue for anyone else? I'm wondering if I should return it, or should I try sanding it. Don't want to mess it up if there's a different version of the 15rd mag I'm supposed to get.

Thanks

[u/BrotherLefthand]

Turks gunna turk