What is the difference between known-replica and known-slave configuration parameters?
I have updated redis version from 3.X to 6.X and now I have both in configuration.
As described here, Redis decided to deprecate use of the word "slave" and replace it with alternative terms whenever it was possible to do so without harming backwards compatibility.
So these terms are synonyms, as you can see in the source code.
When you have multiple values of the same command in a configuration file, as you now do, the last-processed command is what gets used.