If there was one psych principle I wish everyone was aware of (and almost no one is) it's the over-justification effect.

From childhood onwards, when you introduce an extrinsic motivator for something that was intrinsically motivated, it basically 'overwrites' it.

Like to read? If you get an ice cream party for reading, while you won't read that much more than before, after the incentive gets taken back away you'll stop reading as much for pleasure.

The most obvious instance of this is getting paid to do something you used to enjoy.

There's not really a specific 'fix' but introspection about why you do the things you enjoy could help shift it. As you are working on something, recognize your enjoyment of it and set aside thinking about the external rewards you get for it. Maybe even make a change in what you do taking a cut in pay for a work environment that's more fun.

It will be a lifelong battle as long as your profession is the thing you enjoy(ed), but mindfulness on a regular basis about why you intrinsically enjoy the things can mitigate it.