ᐅ Uneven roof battens

Hello everyone,

I’m not exactly sure if this topic is in the right place here, but I couldn’t find a better section. :o

I’m currently building a log cabin and doing a lot of the work myself.
Right now, I’m installing the battens on the roof. Normally that wouldn’t be a big problem, except for the two valleys! 🙁 😕

I was able to install the battens on the large front roof area without any issues. I just measured the rafter length and then calculated the batten spacing.
However, I have an adjacent roof that is a few centimeters lower than the main roof, and here is where I see the problem.

I managed to get everything right with the batten spacing, or so I think, but now I have the problem that all the battens running into the valley are crooked!
They all slope about 2 cm (0.8 inches) downward, but only on the last 1.5 meters (5 feet). I double-checked everything and found that all batten spacings are correct!

How can this be?
Will it be noticeable later once the roof tiles are installed?

Thanks in advance.

Best regards,
Sebastian