First make sure the integration works with a test command in the playground, in my testing the test button wasn't always accurate for the RemoteAccess integration (try without a username/password and it'll say success but fail with commands).
This was my test command in the playground:
!ssh cmd=hostname using=localhost
The next thing to check is to make sure you named your instance `localhost`. The automation is hardcoded with that value for the instance name. The test example above also uses `localhost` so if that fails, the instance name could be the cause. See: https://github.com/demisto/content/blob/d4a6fdd9e50a35e5218bcce7e40d87c95c7ff6c0/Packs/ServerLogs/Sc...
If that's all correct, then check the user you're using for the RemoteAccess instance has read access to the log files in the automations. These are their paths (also hardcoded):
Check with an `ls -a $PATH` while on the host.