Passing variables to service does no work

https://docs.gitlab.com/ee/ci/services/#available-settings-for-services says that since v14.5 I can use variables settings for service

Additional environment variables that are passed exclusively to the service. The syntax is the same as Job Variables.

However, setting the option does not work, it does nothing.

Since there's no way to debug services (!!!!) I checked that this works

services:
    -   name: postgres:13
variables:
    POSTGRES_PASSWORD: pwd

while this does not

services:
    -   name: postgres:13
        variables:
            POSTGRES_PASSWORD: pwd

Pg service is not reachable. No idea whether it failed or what happened to it, I have no way to check logs. Since POSTGRES_PASSWORD is required variable for pg container, I suppose it was not passed to it.

I have same issues with kafka, clickhouse, zk services. I cannot pass variables to them even though docs says otherwise.

E.g. it's impossible to have 2 differently configured zookeeper services in CI now.