sounds possible - is it a small turbo escos with the Lektron valve?

the problem is that the wastegate is not opening for whatever reason. the actuator should open it, so could be a problem with that, but normally they give less boost rather than more - unless it or the wastegate is seized. if you put a pair of grips on the actuator rod, can you move it freely and open the wastegate? try also disconnecting the actuator rod and seeing if the wastegate rotates freely.

if all of that is working fine, it must be the boost control valve itself or the electrical supply to it.