Configure the `default` client to use read mode `:secondary_preferred`. Then configure a `primary` client to use read mode `:primary`. Then:

```
Mongo::Logger.level = Logger::DEBUG

MyModel.where(key: 'existing_key').with(client: :primary).first

1. logs show that model is fetched from primary, as expected

q = MyModel.where(key: 'existing_key')
q.first

1. logs show that model is fetched from secondary, as expected

q.with(client: :primary).first

1. logs show that model is fetched from secondary, which is unexpected
   ```