Hey, project engineer usually refers to the ability to do some project management / business analyst type abilities. Whereas software engineer you have the solution provided and it is your job to implement it.
Project engineering is a touch more rewarding imho than just software as you are usually closer to the customer and can provide solutions that you yourself have come up with.
It's possible to get into entry level positions with only software development experience, but it would be good to brush up on some project management / business analyst type functions but your joining as a junior so it should be known to the employer you'll need some training of some sort.
As for general sde roles, I would say having project engineering experience would actually be a benefit for general sde roles as it means that you can be more dynamic for your employer and you have a better understanding of the challenges that are present in other business areas.