Reduce spurious replication catchup

synapse/replication/tcp/handler.py

@@ -614,7 +614,7 @@ async def _process_position(
         # If the position token matches our current token then we're up to
         # date and there's nothing to do. Otherwise, fetch all updates
         # between then and now.
-        missing_updates = cmd.prev_token != current_token
+        missing_updates = cmd.prev_token > current_token
         while missing_updates:
             # Note: There may very well not be any new updates, but we check to
             # make sure. This can particularly happen for the event stream where
@@ -644,7 +644,7 @@ async def _process_position(
                     [stream.parse_row(row) for row in rows],
                 )
 
-        logger.info("Caught up with stream '%s' to %i", stream_name, cmd.new_token)
+            logger.info("Caught up with stream '%s' to %i", stream_name, current_token)
 
         # We've now caught up to position sent to us, notify handler.
         await self._replication_data_handler.on_position(