Parsing Rule works in Grok Debugger but not when running in logstash with MSSQL

[jbm]

I am attempting to read Microsoft SQL Error logs in via filebeat -> logstash. Testing the rule below against the logs below works in the grok debugger, but fails when running in production.

%{TIMESTAMP_ISO8601:time} %{WORD:event_category}\s+%{WORD:event}:? %{GREEDYDATA:rest_of_message}

2019-04-21 00:15:10.28 Logon       Error: 18456, Severity: 14, State: 38.
2019-04-21 00:15:08.24 Logon       Login succeeded for user 'domain\realuser'. Connection made using Windows authentication. [CLIENT: 192.168.10.10]

In the full logstash config, I have the below snippet, and I am getting the "pre header" tag but not the "parsed header" tag, so I know this bit is where the issue is. The only thing I can make the logs match against in logstash is %{GREEDYDATA}.

if "_grokparsefailure" not in [tags] {
    mutate {
        add_tag => "pre header"
    }
}
grok {
    match => [
        "message", "%{TIMESTAMP_ISO8601:time} %{WORD:event_category}\s+%{WORD:event}:? %{GREEDYDATA:rest_of_message}"
    ]
}
if "_grokparsefailure" not in [tags] {
    mutate {
        add_tag => "parsed header"
    }
}

Is there potential for grokparsing to fail due to encoding? I am pretty sure these logs are utf-16 encoded. I'm just not sure what to try at this point.

Any help is appreciated.

[jbm]

Figured it out! MSSQL Error log is encoded in UTF-16LE. I hadn't put

encoding: utf-16le

in filebeats as part of the input, so that is why it wasn't matching.