A channel shows as disconnected
Work through it in this order. The cause is almost always something that changed outside Convarza, not inside it.
Channels disconnect for a small number of well-understood reasons and almost all of them are external: a token was regenerated, an authorisation lapsed, somebody left the company, or a carrier changed something.
Start from the channel estate on Home, which shows every channel's health in one table. Then work down this list. The order matters — the first two checks take ten seconds and are the answer more often than the rest combined.

Steps
Refresh the status before anything else
The connection card, and trunk status on calling channels, both have a refresh. A status rendered when the page loaded is not evidence about now.
Check the channel is not simply disabled
Enable and disable is a manager action and is very easy to leave off after testing. Disabled is not broken, and it does not report an error.

For token channels, re-issue the token
Telegram, Viber and LINE break the same way: the token was regenerated or expired elsewhere. Get a new one and paste it in.
LINE additionally expires short-lived tokens on a schedule, so a LINE channel that dies after a few weeks almost certainly has one.
For SSO channels, check who authorised it
The Meta channels all depend on one person's authorisation. A departure, a password change or a permissions edit on the business account will end it.
Reconnect with an account that still has rights — and consider whether that account should belong to somebody less likely to leave.
For carrier channels, take the readout to the carrier
Trunk status red with unchanged credentials usually means something moved on their side: an IP allow-list, a certificate, or your permitted concurrency. The gateway config readout is what you send them.
Get an admin if credentials need re-entering
A manager can see health and toggle the channel, but credential fields are admin-only.
Check it worked
After reconnecting, send a real message in and confirm it arrives — do not trust a green dot alone. Then work out what queued up while the channel was down, and tell whoever handles those customers.
The parts people get wrong
- Reconnecting stops the bleeding. It does not tell you who tried to reach you meanwhile, so work out the window and warn whoever owns those customers.
- Add the channel estate to somebody's Monday. A quietly dead channel looks like a quiet week.