I´m not sure why this happens exactly, not sure if it´s something having to do with the version being alpha, but stone walls don´t exactly connect and I would like to know if there´s a solution to this.

It's a bug. Not easy to fix. I fixed it 90% in the 1.18 version. Maybe I can backport the fix. I have to check it out

Ok, thank you for answering! At least I now know if it wasn´t something I messed up or something like that.