Possibly related to ticket #17255, as they are dealing with one of the same Pixelmon config options. The in-game Pixelmon Config menu considers 1024.0 to be the default Raid Shiny rate for 5 star raids even though the actual default Shiny rate for 5 star raids is 512.0.

Whenever you start a world, the Shiny rate for 5 star raids is 512.0. However, whenever you Reset to Default the Raid Shiny rates in the Pixelmon Config, the Shiny rate for 5 star raids becomes 1024.0. This doesn't stick due to the bug in ticket #17255, but it still stands that the game erroneously claims that 1024.0 is the default Shiny rate for 5 star dens even though a new world will have 512.0 as the 5 star den Shiny rate.

How to reproduce:
1) Create a new world
2) Open the Pixelmon Config
3) Click "Raids".
4) Look at the Raid Shiny rate. The Shiny rate for 5 star raids should be 512.0 in the config settings.
5) Click the button to "Reset to Default" next to this config option. The Shiny Rate for 5 star dens should have become 1024.0.

Tested using The Pixelmon Modpack in CurseForge

Good night I tested here and confirmed the bug thanks for the report.

This is a different bug. The bug I posted here is that the default is considered to be 1024.0 rather than 512.0. The bug you claim that it is a duplicate of is a report of the fact that changes to three config settings don't take effect.

sorry I fixed the ticket thank you very much for the report.

Moved to internal, thanks!

Just a side note, as I'm currently testing a fix for this right now - 1024.0 is the actual default value for 5* raids, according to our wiki., so the actual issue was the fact that the changes didn't stick (as in the other ticket) and that the initial value was listed as 512, which it should have always been 1024.