As bizarre as this is, for some reason GarrisonCommander is somehow interfering with the ability you get in Torghast in patch 9.1's Torghast's Anima Power bar, Empowered, which shows up somewhere in the lower middle of the screen when your Torghast power bar reaches a threshold.

The error message that pops up when I click the Empowered button reads, "GarrisonCommander has been blocked from an action only available to the Blizzard UI. You can disable this addon and reload the UI."

Died twice already because of this problem.

Here's a screenshot showing the error message in front of a Torghast boss.

And here's another screenshot, without the error message, showing another instance of this occurring, and the reason the screenshot is without the error message is that I only remembered to screenshot after the death of my character.

This is a video where I talk a bit more about this bug, which makes certain shipyard missions unclickable too. And another similar addon, Covenant Mission Helper, is also somehow linked to this problem because I've had the same exact error message in Torghast that I quoted above but for Covenant Mission Helper instead. I think Blizzard did something to the UI of all mission tables in patch 9.1, and the Activate Empowerment spell in Torghast is somehow related to all this.

In a reply to my posted exact issue for another addon, Covenant Mission Helper, user tflo has thankfully pointed out that this seems to be a Tainting issue, and using the Taintless.xml file available here as part of GarrisonCommander may help avoid this issue and any future similar issues.