Updated Failed state description

ticdc/ticdc-changefeed-overview.md

@@ -19,7 +19,7 @@ The states in the preceding state transfer diagram are described as follows:
 - `Stopped`: The replication task is stopped, because the user manually pauses the changefeed. The changefeed in this state blocks GC operations.
 - `Warning`: The replication task returns an error. The replication cannot continue due to some recoverable errors. The changefeed in this state keeps trying to resume until the state transfers to `Normal`. The maximum retry time is 30 minutes. If it exceeds this time, the changefeed enters a failed state. The changefeed in this state blocks GC operations.
 - `Finished`: The replication task is finished and has reached the preset `TargetTs`. The changefeed in this state does not block GC operations.
-- `Failed`: The replication task fails. Due to some unrecoverable errors, the replication task cannot resume and cannot be recovered. To give you enough time to handle the failure, the changefeed in this state blocks GC operations. The duration of the blockage is specified by the `gc-ttl` parameter, with a default value of 24 hours.
+- `Failed`: The replication task fails. The changefeed in this state will not keep trying to resume.  To give you enough time to handle the failure, the changefeed in this state blocks GC operations. The duration of the blockage is specified by the `gc-ttl` parameter, with a default value of 24 hours. If the underlying issue is resolved within this duration then the changefeed may be resumed. Otherwise, if the changefeed has been in this state for longer than the `gc-ttl` the replication task cannot resume and cannot be recovered.
 
 > **Note:**
 >