Serverless, deploying ElasticSearch to AWS, "Creating elasticsearch domain did not stabilize" - serverless-framework

Question

I'm deploying through Github Actions my Serverless app onto AWS with Lerna, the full output is this one:
Serverless: Checking Stack update progress...
.......
Serverless Error ---------------------------------------
An error occurred: ElasticSearch - Creating Elasticsearch Domain did not stabilize..
Get Support --------------------------------------------
Docs: docs.serverless.com
Bugs: github.com/serverless/serverless/issues
Issues: forum.serverless.com
Your Environment Information ---------------------------
Operating System: linux
Node Version: 14.4.0
Framework Version: 1.65.0
Plugin Version: 3.4.1
SDK Version: 2.3.0
Components Version: 2.22.3
I've tried following this:
Creating Elasticsearch service with AWS Cloudformation: "Creating Elasticsearch Domain did not stabilize"
Which points to:
https://mysteriouscode.io/blog/creating-elasticsearch-domain-did-not-stabilize-cant-create-aws-elasticsearch-5-1-with-cloudformation/
So, I added to my serverless.yml file:
...
ElasticSearch:
Type: 'AWS::Elasticsearch::Domain'
Properties:
ElasticsearchVersion: 7.4
EBSOptions:
EBSEnabled: true
VolumeType: gp2
VolumeSize: 10
ElasticsearchClusterConfig:
InstanceType: ${self:custom.afex.${self:provider.stage}.InstanceType}
InstanceCount: 1
DedicatedMasterEnabled: false
CognitoOptions:
Enabled: true
IdentityPoolId: us-east-2:7f7a3f74-xxxxx
RoleArn: arn:aws:iam::590275261404:role/AfexAmazonESCognitoAccess
UserPoolId: us-east-2_nbiyN8stf
AdvancedOptions: <--------- THIS ARE THE NEEDED LINES
indices.fielddata.cache.size: 40 <--------- THIS ARE THE NEEDED LINES
rest.action.multi.allow_explicit_index: true <--------- THIS ARE THE NEEDED LINES
But there's no change, still I have that error output. Any clue?