dell precision m6800 memory slot not accepting memory

I'm in the process of upgrading my ram when I noticed that 1 of the 2 slots on the dell precision m6800 doesn't "click" and hold the memory. This is the primary memory slot side aka the ones on the bottom of the laptop/not the keyboard side.

Is this normal? I placed it at 25 degree and pushed it down but the slot (B) doesn't hold the memory? Slot A worked fine and held the memory stick.

Fyi, There was no memory in these 2 slots before since the memory occupied were on the keyboard side.. And yes these memory sticks are standard and compatible with the laptop/motherboard.