Why do I keep getting major fluid build up/swelling in my cheek every few weeks?

I have scar tissue in my cheeks from implant removal 2 yrs ago. I've used fillers and then hyaluronadaise to shrink the filler. I haven't had an injection for months but every few weeks 1 of my cheeks will fill up with a big pocket of fluid. My cheek looks like it is twice the size than usual. The fluid is not spread out but is localized to about a 1 inch circle. It will appear in different parts of my cheek. My PS says he has no idea! This has been happening for months. Please help. Thanks