This has been a bug in Mythic Mobs for the items for months and months and I can't find a way to fix it.
If the item has an option to increase the health, it endlessly fills half a heart and then resets that heart and starts again whilst the person is holding the item.
Here is an item pastebin where it occurs - https://pastebin.com/KMBgZA5a
If the item has an option to increase the health, it endlessly fills half a heart and then resets that heart and starts again whilst the person is holding the item.
Here is an item pastebin where it occurs - https://pastebin.com/KMBgZA5a