Push notifications not working after migrating Manual installed to Docker

Description:

Hi,
I've migrated a manually installed Rocketchat 3.5.4 to a 3.6.1 on a docker container. I've also migrated the pre-existent DB data using mongodump and mongorestore from local db to local docker db, and also configured the pre-existen filesystem storage.

After starting rocketchat on docker, it correctly retrieved all the pre-existent content, included the uploaded files.

The problem is that an error appeared: "Push notification are disabled, go to admin/push to re enable it" and noticed it was all disabled. I've reset the settings for this section and that re-enabled the "enable" and "enable gateway" buttons, but when I try to send a test push notification to my user, this error appears:

There are no tokens for this user
[error-no-tokens-for-this-user]

Steps to reproduce:

1. Go to admin / push notifications
2. having them turned on and gateway too, push on send a test notification to my user

Expected behavior:

a push notification should arrive to my mobile device

Actual behavior:

this error appears:

There are no tokens for this user
[error-no-tokens-for-this-user]

Server Setup Information:

• Version of Rocket.Chat Server:
• Operating System: Ubuntu 18.04 LTS
• Deployment Method: docker
• Number of Running Instances: 1
• MongoDB Version:

Client Setup Information

• Desktop App or Browser Version: Desktop app 2.17.7
• Operating System: Windows 10 Pro

Start by reproducing the migration from Rocket.Chat 3.5.4 to 3.6.1 in Docker with the restored MongoDB data and configured filesystem storage. Check Admin > Push Notifications and the test notification path; done means the migrated user has a token and a test push reaches the mobile device without error-no-tokens-for-this-user.