I finished the game two weeks ago and I decided to start a new game, with the 1.06 patch.

I'm in the first region of the game, level one... And boy, either I didn't remember leveling was so slow, either something is awfully wrong. I finished a quest about a cart lost in the swamp and I won a wopping... 9xp. With a Lvl1 character. Then I killed 5 wolves and a warg: 2xp for the whole group. Is it linked to the difficulty level, or is the game still screwed ?

I don't think so,but you pick up something on Nexus:
http://www.nexusmods.com/witcher3/mods/searchresults/?src_cat=5

XP has worked perfectly for me since the 1.05 patch, I replayed a lot of the game since it came out and ended up level 35 having completed the main quest and a lot (though not all) of the side quests.

Ignore gunsynd's advice, the mods listed were made to be applied before the 1.05 patch was released, or change the levelling experience for the game completely.

XP given definitely scales with character level and at the beginning of the game you level extremely slowly (you'll definitely get barley anything from killing random enemies like wolves).

You should hit level 4 as you're leaving White Orchard (assuming you do absolutely everything available there).

I could reach level 35 50% to 36 by the end of the game.

DONT USE MODS.... PLAY IT LIKE A REAL PLAYER, NOT LIKE A MOD CRYBABY THAT WANTS EVERYTHING EASY.

Yes, no need to use any mods. It works fine. You'll get more XP than you really need during the course of the game.

Well, thanks for your answers. I finished the game with a lvl37 character the first time, and I thought I was lvl5 when I left the tutorial area during my first run. Here, I was barely lvl 3, and I did everything (including visiting the entire map). So I guess this has to do with the difficulty level being up.

I love the title of this topic - "XP Bug: Is it solved ?? SOLVED"