There are several reasons a thread may not appear in your Shortwave inbox. Here’s how to troubleshoot and fix these cases:
There are times where Shortwave needs to sync large amounts of data with Gmail, causing the Shortwave inbox to be slow to update. This can happen during initial import immediately after signing up, historic import after upgrading, or during a large bulk action. This is just a temporary disruption as the sync completes. It can take days to finish syncing in the very worst of cases, but your Shortwave inbox will eventually catch back up to Gmail and sync in near real-time.
Messages trashed or marked as spam do not show up in Shortwave. You will have to view these threads back in Gmail. Untrashing or reporting them as "not spam" from Gmail will bring them back to your Shortwave inbox.
Try revoking access to the other unused email services connected to your account. You can remove connected apps from your Google Account settings via Third-party apps & services > Access to > Gmail and by clicking "Delete all connections you have with [app]."
Guides
The Shortwave Method
Shortwave AI Assistant
Migrating from Gmail
Compose & send
Bundles
Smart Labels
Shortwave for teams
Billing
Security
How-tos
Download desktop
Default email app
Enable push notifications
Troubleshoot push notifications
Manage multiple accounts
Sync Gmail settings
Integrate Shortwave with your CRM
Troubleshoot missing threads
Print a message
Download EML file
Google Advanced Protection
Import full history
Downgrade account
Delete account