a commond problem with beginners is they tend to roll the guitar body so the can see where they put thier fingers. This puts more bend in your wrist and pulls your fingers at an angle. The problem becomes worse when the guitar body is thicker. You can also raise the neck higher to can the angle.
I try to exercise my fingers and wrist to expand stretch and warm them up. I wedge my right wrist between my left hand finger and hold for 30 seconds.
Try doing spider push-ups. Put finger together push in and out several times.
You can spread them as far as possible at the same time.
Last, let your arms drop to your side. let them relax until until they can shake like rags. Skake vigoursly. Then let your fingers do the walking.
I hope this works for some..
Y'all have a great day and keep on pickin'
Gordon