Shorten API generated URL yields an "Unable to Parse URL" error in Kibana

[valguz]

Kibana version: 6.3.1

Elasticsearch version: 6.3.1

Server OS version: Cloud

Browser version: Chrome 69.0.3497.100 64-bit

Browser OS version: Mac OS X High Sierra

Original install method (e.g. download page, yum, from source, etc.): Cloud

Describe the bug: Shorten API generated URL yields an "Unable to Parse URL" error in Kibana

Steps to reproduce:

1. Open up a Kibana page, and grab the URL
2. Craft your curl statement like the docs indicate, as such:
   valguzman@elastic-lappy[~] $ curl -u <redacted-username>:<redacted-password> -X POST "https://2c43139999e9401d89ec6ac60ea000cd.us-west1.gcp.cloud.es.io:9243/shorten" -H 'kbn-xsrf: true' -H 'Content-Type: application/json' -d' { "url": "/app/kibana#/discover?_g=()&_a=(columns:!(_source),index:c03c43b0-b074-11e8-83dc-99889e2f1791,interval:auto,query:(language:lucene,query:''),sort:!(_score,desc))" }'
3. It correctly yields the 32 character string: 03d6b58532b8b315a1d4b2239e46b39a
4. I navigate through the browser to: https://2c43139999e9401d89ec6ac60ea000cd.us-west1.gcp.cloud.es.io:9243/goto/03d6b58532b8b315a1d4b2239e46b39a

Expected behavior: It loads the appropriate kibana screen for the URL I shortened
Actual behavior: Unable to parse URL error message

Screenshots (if relevant):

Errors in browser console (if relevant):

INFO: 2018-11-05T20:50:56Z
  Adding connection to https://2c43139999e9401d89ec6ac60ea000cd.us-west1.gcp.cloud.es.io:9243/elasticsearch


kibana.bundle.js:7 setting active api to []
2vendors.bundle.js:19 rison parser error:  missing ','
commons.bundle.js:3 handle each segment
commons.bundle.js:3 complete in 0.10ms
commons.bundle.js:3 flatten hit and count fields
commons.bundle.js:3 complete in 0.40ms

Any additional context: This was reported through a support ticket for an on premises install, but I was able to replicate in the cloud as well.

Additionally, if I use the non-deprecated version /api/shorten_url instead of /shorten I get a 404:

valguzman@elastic-lappy[~] $ curl -u <redacted-username>:<redacted-password> -X POST "https://2c43139999e9401d89ec6ac60ea000cd.us-west1.gcp.cloud.es.io:9243/api/shorten_url" -H 'kbn-xsrf: true' -H 'Content-Type: application/json' -d' { "url": "/app/kibana#/discover?_g=()&_a=(columns:!(_source),index:c03c43b0-b074-11e8-83dc-99889e2f1791,interval:auto,query:(language:lucene,query:''),sort:!(_score,desc))" }'
{"statusCode":404,"error":"Not Found"}