Edit: Just copy the original filename, Chinese and all, to a custom RERF file. It tested fine with the factory tests and also custom test parts I made. I didn’t test with only “R_E_R_F.px6s” as the filename as I proved the original filename works fine with custom models.
Edit2: I had the motivation to check the file today without that Chinese and it works fine as well.
Just got a new Anycubic Photon Mono X 6Ks and the RERF file on the included USB has Chinese characters in the name. (“R_E_R_Fchch.px6s” / ch being Chinese characters…) Does the printer require those characters for custom RERF test prints, or is it actually just “R_E_R_F.px6s”?
The documentation is unclear and online searching is jumbled with several issues regarding this filename across different printer models.