I have a Wolfgon electrical pressure cooker. I like it a lot.
However, I wonder why you use so much times cooking. When cooking spare rib soup, I put on meat program which cooks for 20 minutes. It cooked nearly perfect soup. When I cook 八宝粥, I put on rice program which is 6 minutes and do a very good job. However, you have to be patient waiting the pressure to be fully released itself. The program time is only the cooking time when the pressure is maintained at the specified ones. Therefore, it takes some time to build to the specified pressure and some additional time after the program is done to release the pressure.
If you cook 粉蒸肉, doubling the meat cooking time to 35 to 40 minutes will do an excellent job.
Always remember to let the cooker release the pressure itself. Considerable cooking is actually done during this pressure releasing time.
Have good time with your pressure cooker.