[Mezzie]

Couch it in how you want to contribute to your team.

Instead of "I don't want interesting work", say you want to help support members of the team who are looking for new opportunities, or something like that. There's X work maintaining the codebase and Y work on new and shiny projects and Z employees. Suggest perhaps cross-training in other people's less-stressful work (if there is any).

If you say that, then your manager (in their head), can be thinking, "Okay so we have this new project, and songzme doesn't want it, but her coworker does, so if songzme can pick up some of the maintenance work, the coworker will have time for new project." Obviously, keep your total workload under control, but a manager's job is to get a team to do something. It's fine to play support, just be open to it.

It doesn't have to be permanent. I've had time periods when I've volunteered for projects and others when I'm not interested due to external factors. During those times, I just did more of the team's work that required the least 'brain'. Which is great for the team members who are feeling bored and want to try something new.