As of Patch 8.2.0, insecurely hooking OnModifiedClick spreads taint everywhere. It'll taint comparison tooltips (they don't work in combat), it taints Azerite trait selection windows (also don't work in combat), and it can even taint the dressing room (doesn't work in combat from bags).

There are alternatives, but I don't know your particular use case. Quite a lot of chatter has been made in #wowuidev in Freenode IRC about it.

This will likely disappear with the 8.3 UI updates currently being worked on. Closing.