So there are 9 specs they are named differently in the game and in the files:
GHOST Fire Support => RT_Marksman1
GHOST Infiltrator => RT_Marksman2
GHOST Watcher => RT_Marksman3
GHOST Rampager => RT_Berserker1
GHOST Berserker => RT_Berserker2
GHOST Operator => RT_Berserker3
GHOST Clairvoyant => RT_Gatherer1
GHOST Gatherer => RT_Gatherer2
GHOST Telepath => RT_Gatherer3

(Keep in mind that each of these 3 make for one of the three classes in rising tides mod.)

Now the ability "Teek" is in Gatherer1, Breserker1 and in Marksman2 and the other ability "Fade" is in Gatherer2, Breserker2 and in Marksman2. What you do is find these three in the XComRPG.ini in your mod folder (\SteamLibrary\steamapps\workshop\content\268500\2765852780\Config)

In there find the corresponding trees and underneath them change the "+AdditionalSquaddieAbilities" to ";+AdditionalSquaddieAbilities=" (add a ; before the line)
The full line for each class is:
Marksman => +AdditionalSquaddieAbilities=ScopedAndDropped
Berserker => +AdditionalSquaddieAbilities=BumpInTheNight and +AdditionalSquaddieAbilities=RTBerserkerKnifeAttack (change both just in case)
Gatherer => +AdditionalSquaddieAbilities=OverTheShoulder

IMPORTANT: DON'T change all of these lines just the ones in Gatherer1, Breserker1, Marksman2, Gatherer2 and Breserker2 otherwise the mod won't work correctly.

Now once back in game you shouldn't face the same problem again as long as you pick the three specs that work together (Marksman1, 2 and 3 or Berserker1, 2...) and if you just want to pick one of these then make sure you also pick one from a tree that gives you the required ability. e.g: say you just wanna use abilities from Gatherer1 in order for the abilities to work correctly you have to pick one from Gatherer3.

Note: I have not tested this to see what happens when you don't have "Scoped And Dropped, Bump In The Night, Berserker Knife Attack or Over The Shoulder the mod author here says it's necessary and I'm too tired to try to figure it out xD.

If someone found a better fix or maybe knows how I can make the changes I suggested with the perk please let me know.