Originally posted by Altimely:

Slope Hit Fix mod
https://www.nexusmods.com/valheim/mods/727
Also applies to aiming while chopping and mining

But this should not require a mod to fix this is something that should be fixed by the Developers if a modder can fix it then no absolute reason whatsoever the developers not to be able to fix it or at the very least buy the mod from the mod developer and implemented into the base game