Have the same problem with my Samsung SH-W162C and LG GSA-4120B.
Media TDK x 8 and x 16 plus Memorex x 8.
Example with TDK 8.
It start perfectly with a spped of 5.5. Goes up to7.7-8 when the radius increases. But at app. 35 % suddenly the buffer dropps to 0 and the spped falls.
Windows on partion C, Imgburn on same drive but another partion.
The image on its own drive.
06-03-23
Have now backed to version 1.1.0.0 and can now burn without any problems