Instance specific actions lost when changing between hud layouts

Self explanatory so not filling out all the additional info. I can't believe this is a bug and maybe I'm just stupid and don't know how to get the actions back, but this has happened to me during multiple story instances where you play as other characters. I usually play on whm with a different hud layout and so when I get to play a dps/tank character I switch to a dps style hud via a macro and vice versa, and it has the effect of removing the instance specific actions with no (obvious) way of getting them back.

I tried searching for other threads that reported this, but it's a bit tricky as a thread title could be defined in any number of ways.

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