Peter’s very helpful guide for catching up on a busy Slack workspace:

1. Open the Slack App
2. Most messages sent overnight will not display at this point
3. Help > Troubleshooting > Clear cache and exit
4. Re-open Slack App
5. Catch up on all messages
6. As you navigate, Slack will display read channels as unread.
7. Press escape on these channels
8. As you navigate, Slack will return to the wrong point in the timeline
9. Help > Troubleshooting > Clear cache and exit
10. Re-open Slack App
11. Wistfully remember when Slack was simpler and worked.