Kala U-Bass Solid Body 4-String CR

Before buying it, I saw some reviews about it, and many people said there was no way to tune the E string, and that they didn’t know how to fix it
I play bass since 16 years, since more than 10 I do it as my profession, and I’ve owned almost 40 different basses in my life (including 2 Kala Ukebasses), so I thought with some experience I could work around the issue

It turns out, all those people were right… ahah
It’s a pity, cause the other strings work well, but there’s something that doesn’t quite work on the E: when you play the open string it goes up and down on pitch, same on the frets and even the sound of it on open string or frets is unstable.
I narrowed it down to 2 options: either the brand that makes the strings can’t do a proper E string (could totally be, considering the small scale), or the tuning peg is not working as it should, and perhaps doesn’t have the right angle.

Maybe that’s something that you can fix with a luthier, or change strings or change the tuning peg, but for sure no one wants to try their luck with this on an instrument bought new, risking to spend more money on it and maybe even not solving the problem.
It’s really a pity, cause the instrument looks lovely, and has potential; I hope Kala fixes this issue.