I had this type of thing too. They happen quite frequently but I have no idea what they are. They look like cyan curved trails.
I posted a video of them in the Twin wotter DCH6 thread as that waa what I was flying at the time. I also do not have thermals display turned on. I’ve seen them on a few flights now but not every flight. I have no idea what is causing them or how to turn them off.
Short video in linked post below.