Lens mount problem

[BobHoward42]

I have a 6400 and a 6000 along with an older 50 to 210 Sony lens with an E mount. The lens mounts fine on the 6000 and has been one of my favorite lenses for bird photos but when I got my 6400 this lens won’t mount all the way. It goes on but then when I twist it it won’t go to the click so the electronics don’t work. All my other lenses worked just fine. Has anybody else run into this situation? .