The integration failed to send a message to "#channel" because user "rocket.cat" doesn't have permission or is not a member of the channel

Description:

Last night I updated my server to the latest version (3.4.2) and I now have a message in my logs telling me that the user "rocket.cat" (bot) can't send messages sometimes.

Steps to reproduce:

I can't reproduce the problem when I do a curl on the API manually I don't get an error message that appears.

Expected behavior:

Do not have WARNING in the logs.

Actual behavior:

Command sent by my monitoring system to RocketChat:

curl -X POST --data-urlencode "payload={\"username\":\"Zabbix\",\"text\":\":x: *More than 99% used on dataset test/torture on srv-63*\"}" https://chat.cosium.com/hooks/XXXXXXXXXXX

Log of my monitoring system telling me that it sent this message:

2020-07-22 14:52:08 | XXXXXXXXXXX | :x: *More than 99% used on zpool test on srv-63*

Error from the RocketChat server telling me that it can't send the message because it doesn't have the rights:

Jul 22 14:52:08 rocketchat rocketchat[3662]: Warning: The integration "sysnet-test" failed to send a message to "#sysnet-test" because user "rocket.cat" doesn't have permission or is not a member of the channel.

The alert is sent in the channel on RocketChat:

Zabbix @rocket.cat Bot 2:52 PM
❌ More than 99% used on dataset test/torture on srv-63

I don't understand why he's telling me he can't send it if he's sending it anyway. As I said before, it is impossible to reproduce the problem manually and it happens randomly on some messages.

Server Setup Information:

• Version of Rocket.Chat Server: 3.4.2
• Operating System:
• Deployment Method: manual
• Number of Running Instances: 1
• DB Replicaset Oplog: Enabled
• NodeJS Version: 12.18.2
• MongoDB Version: 3.6.16

Relevant logs:

Jul 22 14:52:08 rocketchat rocketchat[3662]: Warning: The integration "sysnet-test" failed to send a message to "#sysnet-test" because user "rocket.cat" doesn't have permission or is not a member of the channel.
Jul 22 14:52:08 rocketchat rocketchat[3662]: This behavior is deprecated and starting from version v4.0.0 the following error will be thrown and the message will not be sent.
Jul 22 14:52:08 rocketchat rocketchat[3662]: Error: error-not-allowed
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at app/authorization/server/functions/canSendMessage.js:19:9
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at /home/rocket/3.4.2/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/fiber_pool.js:43:40
Jul 22 14:52:08 rocketchat rocketchat[3662]:  => awaited here:
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at Function.Promise.await (/home/rocket/3.4.2/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/promise_server.js:56:12)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at validateRoomMessagePermissions (app/authorization/server/functions/canSendMessage.js:48:101)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at processWebhookMessage (app/lib/server/functions/processWebhookMessage.js:90:4)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at Object.executeIntegrationRest (app/integrations/server/api/api.js:250:19)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at app/api/server/api.js:388:82
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1234:12)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at Object._internalRouteActionHandler [as action] (app/api/server/api.js:388:39)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at Route.share.Route.Route._callEndpoint (packages/nimble_restivus/lib/route.coffee:150:32)
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at packages/nimble_restivus/lib/route.coffee:59:33
Jul 22 14:52:08 rocketchat rocketchat[3662]:     at packages/simple_json-routes.js:98:9