With it set to the following it should all work correctly.
Code
; Maximum amount of chunks to check for retrogen viability each tick.
; Retrogen is the retroactive generation of terrain features, e.g. ores and trees.
; Set it to 0 to disable retrogen.
; When enabling this the recommended value is 16
retrogenCheckLimit = 16
; Maximum amount of chunks to process for retrogen each tick.
; Values exceeding retrogenCheckLimit are being truncated.
retrogenUpdateLimit = 2
Display More
You can leave it on too, it will only regenerate a chunk once.