Problems when upgrading from 7.5.2 to 7.6.0

Ok, thanks, that clarifies the situation.

It seems that Elasticsearch is picking up these settings twice for some reason. Can you describe your setup a bit more precisely? Are you using docker-compose like in the manual? If so, can you share the full docker-compose.yml? If not, how are you orchestrating these nodes?

(I tried running docker-compose as documented and did not see the effect you are describing)