Help - Why does my sleeve look like this?

I don't understand why the beginning of my sleeve has a bulge like that? I tried to pick up more steeches than the patern says but I still have the problem. Will blocking fix the problem (it's knitting for olive cotton merino)?

Thanks a lot !

https://preview.redd.it/vz963d8cosye1.jpg?width=3024&format=pjpg&auto=webp&s=86a9dc39cdc7ceca31d7cf4f0497ab72c55e9807