Ok, so according to the electrical drawing the solenoid valves were connected correctly before I swapped the connections. For the time being, Y29 and Y30 will be bypassed. I may never connect them back up, but I think I will try and find out why they are not working as intended.

The solenoid valves do work when energized on the bench, so that isn't the issue.

Also, in case anyone cares, the wastgate moves freely and the actuator works as expected.