> Feeling a little bored or burnt out with the main title but still wanting to work on something
I don't know if that's the case here, but as a dev myself I can 100% confirm that this is a thing.
Sometimes it simply gets mentally tiresome to work on the same project all the time.
If it's basically a choice between procrastination and doing almost nothing, or working on a different project instead, the latter is in my opinion the lesser evil.
Plus, sometimes you get new ideas from those side-projects, or end up learning something or making something for them that you can use in the main project as well.