A Season is split into several Rounds which last 2 weeks. (At the end of the Season which lasts 10 weeks, the whole territory map gets reset.)
In order to get this achievement you need to come back and deploy assets at least once every 2 weeks, 5 times. You can see what round is currently running by looking in the top right corner of the Multiplayer Map.NOTE: "Seems the first round didn't count, now that the second round has started I'm on 20%. Means you won't be able to get the achievement until your 6th played round."
According to DJSHYNE21
I played in each round of the season and had to play a match after the season ended in order to deploy the asset and get the achievement to pop....