''Tuned in" achievement bugged, not popping

[B.ArC~DmC]

I did find all four radio frequency, and bring them back to Gina. The achievement did not pop for me. My guess of the problem is that I brought last two radio frequency at once.

[II-Corps Redleader]

I believe I might have a similar issue, I had three in my inventory.
I gave one to Gina and then my inventory was empty ...

[Kanooshka]

Same issue here

[Udders]

I think from reading other comments surrounding this achievement that there is another set of radio frequencies to get in a later area you progress to in the game. So from what I can tell you have only found half so far required for the achievement. There is 4 in Gizeh and another 4 in Sukhothai which will give you the 8 radio frequencies needed