Hi MagmaMcFry, tks for ur answer. Tried that and didn't worked, maybe beacause it's an option that modify the map generation settings, mid game it seems to do nothing :/
It's working perfectly for me. Note that you can't hide any technologies that you've already researched. These options do not change any map generation settings, otherwise you couldn't even click them midgame. Did you remember to click on "Confirm" after changing the settings?