This is the emails between the YouTuber YGK3D and Anycubic, it seems like they won’t send 3D printers to reviewers who mention their GPL3 license violations.
tl;dr Anycubic uses open-source software for their firmware, but doesn’t make it public as per license agreement, and they don’t seem to be friendly to anyone who calls this out.
More info: https://www.youtube.com/post/UgkxIMpZTkXqFo0H6pDwhZpdYqMYvLhPvWA5?lc=UgxA-4LYvwrnonXuXsZ4AaABAg
Anycubic has a terrible reputation in the 3D printing community. I remember I had a problem with one of their products years ago and they made warrantee service contingent on giving them a 5 star rating on Amazon.
Anycubic is just a garbage company. They make Bambu labs look like hero’s.