The place you want to go is Lassarga

It is south of Dakhla center so not where all other camps are located.
But there is an Ion club www.ion-club.net/dakhla-lassarga/
And you can ride waves in front of the camp (point break, wind is side-off) and go to the lagoon for flat water using a shuttle (tractor with a ben)

There are more waves in the winter, and more wind in the summer
To me (been there 10x) the best time to go is april/mai/june/september/october
Winter is risky for the wind, juli/august it blows sometimes too hard

Amazing place for sure