Welcome to the forum.
From description it seems you might suffering from trigger finger
.In trigger finger, also known as stenosing tenosynovitis
, one of your fingers or your thumb gets stuck in a bent position and then straightens with a snap — like a trigger being pulled and released. For mild cases splinting, finger exercise required.I would suggest getting this evaluated by an orthopedician for an accurate diagnosis and appropriate management.
I hope this is helpful to you.