Wastegate Actuator Replaced , Engine Light On A Day Later ?

So basically the situation was my check engine light was on , turbo was under-boosting. I had done some research finding out it was a problem with the waste gate actuator. In my case it couldn’t be adjusted because the value of the actuator was constantly going up and down according to the mechanic that ran a diagnostic. It explains why somedays the engine light would be on and other times not. Basically I paid about 500$ for them to replace it because he told me it needed to be replaced , but now my engine light is on a day later. Is it common for the waste-gate to need an adjustment so soon after replacement? And I don’t want to take it to the shop every time this happens.