i had problems with DEDICATION and EL MEXICANO.

I didn't had any problem, I unlocked all achievements as intended

yes, i unlocked it already by replaying the campaign.

a few other achievements are also glitchy, so my recommendation would be to backup the save files after each mission to avoid frustration later :)

It just mentions, "collect all items on the Intel Board'. Most probably you got it, just the game is somewhat laggy in regards to the achievements. At least from my side, it takes up to few minutes until the achievement comes up. Havent experienced anything like this.

for some reason DEDICATION achievement doesn't unlock after visiting Intel board when all DEA missions are completed. are there any other requirements for the achievement, is it necessary to finish both campaigns?