If you are using Gimp 2.10 (as indicated) no use putting anything in "users\username\gim2.8\patterns2"
The Gimp 2.10 profile will be "C:\Users\your-name\AppData\Roaming\GIMP\2.10\.......
The Gimp 2.10 profile will be "C:\Users\your-name\AppData\Roaming\GIMP\2.10\.......