Hello,
You'll need to provide more information to help us pin-point the problem:
* Is sf_el_gx using background layer of the display (it's recommended as it has higher priority on the gpx bus than the foreground layer)?
* Are they using D/AVE2D drawing engine?
* Are they using screen rotation feature (it can be problematic when D/AVE2D is active)?
* What color depth are they using (using 24/32-bit color depth will double the bandwidth required for updating the display)?
* What panel clock division ratio they're using (as above, higher update rate will need more bandwidth).
* What else is running in their project?
* What are DRW and GLCDC LINE DETECT interrupt priorities?
Regards