This is a rare problem and you may want to have another scar revision, however, you should ask your self and your doctor if the problem is the stitching by the doctor, the suture material or your skin/healing.
Scar healing and blepharoplasty
If the scars are going through a similar process as the first time, it may benefit you to use some types of scar treatment during the healing process such as mederma, scar fade gel, scar recovery gel, etc. Sometimes topical silicone sheeting and non ablative laser treatments may help. I would discuss your concerns with your surgeon for their opinion.
Surgical scar problems
Surgical scar problems due to healing issues may represent an underlying metabolic or medical problem. If performed properly, upper eyelid incisions should heal with essentially little to no visible scar. Since you are having problems again after scar revision, efforts should be made to look for an underlying medical problem. Once you have determined your health is optimized, consultation with a board certified Plastic Surgeon is essential to obtaining the ideal results that you are seeking.Good luck with your surgery!