Charm's Magnetic enchantment causes mined blocks to go directly to your inventory. When mining a Prismarine Coral Block that has a Prismarine Coral or Coral Fan on it, the block drops as if there were no Magnetic enchantment on the tool. This problem does not occur with Elder Prismarine Coral Blocks; they are magnetized normally.

I previously noticed this problem in the 1.14.4 version as well, but at the time I wasn't certain what the conditions were.

svenhjol/Charm#235

This is an issue on their side from what I can tell, closing this. If more info is gathered about it and it seems it's on our side then re-open the issue. Thanks for the report.