ES 7.11.2 / Kibana error : index has lifecycle error

[webfr]

Hello guys,
could you help me please fixing this issue?

Index lifecycle error
illegal_argument_exception: setting [index.lifecycle.rollover_alias] for index [myindex] is empty or not defined

index setting:

{
"index.blocks.read_only_allow_delete": "false",
"index.query.default_field": [
"*"
],
"index.refresh_interval": "1s",
"index.write.wait_for_active_shards": "1",
"index.lifecycle.name": "myindex",
"index.routing.allocation.include._tier_preference": "data_content",
"index.priority": "100",
"index.number_of_replicas": "1"
}

index lifecycle policy (show request):
PUT _ilm/policy/myindex
{
"policy": {
"phases": {
"hot": {
"min_age": "0ms",
"actions": {
"rollover": {
"max_size": "5gb",
"max_age": "365d"
},
"set_priority": {
"priority": 100
}
}
}
}
}
}

Thanks a lot.

[webfr]

Update : understood this should be applied to new index so I restarted from scratch using Tutorial: Automate rollover with ILM | Elasticsearch Guide [7.11] | Elastic
Let's see...