If the company pays to do a project where nothing happens for six months and it keeps paying, they are probably okay with a result, otherwise they would listen to your constructive proposals on how to improve the process. Or fired you. Do they say they like what you do there or not? It's important to have a perspective here.
There are two ways to deal with it -- one is reframing it. Sure, it's not the most exciting project, but doing the boring stuff and being persistent at that is a challenge of it's own. Challenge doesn't have to be technical, especially for the product owner.
Second is to give it less time and space in your mind. Physically not being in the same environment, closing the laptop, taking a lunch break and taking a walk. You are not supposed to care about something more than the company owner and your boss anyway, unless you have a direct financial incentive tied to results of the project (which in Sweden your probably not have).
While you give less time and space to the annoying part of the job, find something that displaces it. Vibecode an open source project, learn Arabic, Japanese or whatever, go skuba diving on vacation, do some serious gaming or religion. Something bigger than work.