JQL issueLinkType "!=" and "Not In" Operators Not Recognized

[Deleted user]

I'm trying to filter tickets by the types of attached tickets they don't have e.g. I want all tickets that aren't already related to another ticket.
In JQL I add in "AND issueLinkType = "relates to"" to my filter and I get all the predicable results
But when I add in a ! and change it to "AND issueLinkType != "relates to"" I get nothing. No results.

I've tried lots of variations with lots of different ticket types. I am able to use "in" but not "not in". I checked the documentation for the type of Jira I am using and those operators are supported and there are even examples that do the exact thing I'm trying to do.
What am I missing?

[Jira Guru · Accepted solution]

1. I suggest you try this (it worked for me).
2. First search for issues with the relates to issue link type. For example, 

Project = "abcd" and issuelinktype in ("relates to")

Note: replace Project = "abcd" with your scenario specific conditions.

3. Save the above search as a filter, for example, i saved my filter as 

rellated_issues

• 
  4. Now run your issue search with your scenario specificconditions and jusr append the following to the end:

and filter not in (related_issues)

• Note: replace "related _issues" with the filter name of yours.

[Martin Fukatko]

Thanks, this way solves my problem too.