I noticed that when I equip the Polynesian tattoo on my left arm, the right one automatically equips it as well from the first person perspective, even though I don't have it unlocked. I don't know if this issue affects all tattoos or just this particular one.

Here's some screenshots where you can see that I have the Wolf tattoo equipped on my right arm and in game it shows the Polynesian on both arms:
Insurgency Sandstorm Screenshot 2020.02.14 - 12.23.00.49.jpg

Insurgency Sandstorm Screenshot 2020.02.14 - 12.23.20.87.jpg