Jira says that the JQL is incorrect even is it correct one.

Jira said that the JQL is incorrect if you add brackets "()" to the last logic part of your nested query. If you add brackets to the others statements/part of the JQL there won't be any error.

Current behaviour:

Correct JQL:

Incorrect JQL:

Expected behaviour:

Both JQL should be correct -

Workaround

Remove brackets in your last nested statement.