What are you trying to gift out? Some items are not giftable.
What web browser are you using? Sometimes trying a different browser helps with proshop errors.
or...
You just joined on Sept 18th and already have gifted out 4 sleeves of balls. I wouldn't be surprised if they are looking in to that.
Not an accusation, just with all of the multi-account suspicions, maybe they are trying a bit harder to catch them.