I take it you mean the red “R” button on the R/C. If so then I’ve had that happen often for no apparent reason. It happens then it clears up. I’ve raised it on the official Freesat forum in the past and it simply got ignored. Since it only happens on the occasional channel then I’ve learned to live with it as you can press the OK button and get a menu that offers recording.
However, if you’re getting it as a permanent problem then follow Barry’s advice.