What could be causing persistant edema after Hyaluronidase?

I had my fillers dissolved ultrasound targeted in my nasolabial folds and smile lines. I had the filler for 8 months. Residual filler isn’t seen in ultrasound. But till now, 2 months out from dissolving i have a persistent edema in my left face. I wonder about the reason for this? I had a second opinion under ultrasound from another aesthetic doctor and he didn’t find filler as well. What could be the underlying issue? Thank you in advance