Decisions Tab has disappeared from Team or Channel
If the Decisions tab is no longer available for a Team and Channel, follow these steps to add again
Option 1
- Click Apps, in the bottom left Teams sidebar
- Search for Decisions
- Click Open

Option 2
- Go to the Team/Channel where the Decisions tab is missing
- Click "+"
- Click More apps
- In the next window, search for Decisions
- Click Open