Suppose you hover cursor over an item (that you aren’t wearing), and it has “health and GB chance” affix. You can see tooltip with icon and affixes. The GB affix will read “X health” and on a second line “Y% chance to get a glancing blow”.
Now if you press Ctrl to compare this item with the one you are wearing, the GB affix will chance to just “X health”.
(The item itself is not changes, it’s just a visual bug)
I’m not sure if this happens only with GB affixes, or any multiline affix.
I will provide more details and a screenshot later, if needed.