[oregen.dark_animica_ore]
	#Generate Dark Animica Ore in The Nether - [true/false]
	generate_dark_animica = true
	#Maximum height for Dark Animica Ore generation - default = 255
	#Range: 0 ~ 255
	dark_animica_max_height = 255
	#Size of Dark Animica Ore veins - default = 6
	#Range: 0 ~ 100

! light_animica_size = 6
#Number of Dark Animica Ore veins generated in a chunk - default = 16
#Range: 0 ~ 100
! dark_animica_size = 16
#Minimum height for Dark Animica Ore generation - default = 20
#Range: 0 ~ 255
dark_animica_min_height = 255

couple issues here

This issue should be fixed in the new Ores and Metals-1.15.2-1.2.0.1 update.
Thanks for letting me know!