Duplicate rows returned with worklog entries. I just need the latest entry

I made this query which works. The issue is it displays rows for every worklog. I only need the latest worklog for each incident.

SELECT DISTINCT
`HPD:Help Desk`.`Incident Number` AS Incident_Number,
`HPD:Help Desk`.`Status` AS Status,
`HPD:Help Desk`.`Priority` AS Priority,
`HPD:Help Desk`.`Assigned Group` AS Assigned_Group,
`HPD:Help Desk`.`Assignee` AS Assignee,
`HPD:Help Desk`.`Submit Date` AS Submit_Date,
`HPD:Help Desk`.`Last Modified Date` AS Last_Modified_Date,
`HPD:Help Desk`.`Description` AS Description,
`HPD:Help Desk`.`Submitter` AS Submitter,
`HPD:Search-Worklog`.`Worklog Description` AS Worklog_Description,
`HPD:Search-Worklog`.`Work Log ID` AS Work_Log_ID
FROM
`HPD:Help Desk` 
INNER JOIN `HPD:Search-Worklog` on (`HPD:Search-Worklog`.`InstanceId` = `HPD:Help Desk`.`InstanceId`)
WHERE 
(`HPD:Help Desk`.`Status` in ('Assigned','Pending','In Progress')
And `HPD:Help Desk`.`Submit Date` >= $__from/1000 and `HPD:Help Desk`.`Submit Date` <= $__to/1000)
ORDER BY
`HPD:Help Desk`.`Submit Date` ASC
LIMIT 20

I've tried the HPD:Help Desk, HPD:Worklog, and HPD:Search-Worklog forms. I've also tried using the CASE statement to only display the latest/max work log id for each incident to no luck. I'm sure I'm missing something obvious/simple.

Assuming a recent version of MySQL(or variant of) that supports window function, a very effective way to get "the most recent" of something is to use row_number() over(). Within the over clause use partition by to control what will trigger a reset of row numbering and use the order by to control which row within the partition that gets the row number 1. Now to get "the most recent" requires some column in the worklog table that enables this - I have assumed a timestamp column (worklog_entry_date exists in that table (worklog_entry_date), you will need to substitute the actual column(s) that determine "most recent". Nest the current query one layer so that you can then filter for when row numbers are 1 - these will then be "the most recent" rows:

SELECT
*
FROM (
SELECT
h.`Incident Number` AS Incident_Number
, h.`Status` AS STATUS
, h.`Priority` AS Priority
, h.`Assigned Group` AS Assigned_Group
, h.`Assignee` AS Assignee
, h.`Submit Date` AS Submit_Date
, h.`Last Modified Date` AS Last_Modified_Date
, h.`Description` AS Description
, h.`Submitter` AS Submitter
, w.`Worklog Description` AS Worklog_Description
, w.`Work Log ID` AS Work_Log_ID
, row_number() over(partition by h.`Incident Number`
order by w.worklog_entry_date DESC) as rn
FROM `HPD: HELP Desk` h
INNER JOIN `HPD: Search - Worklog` w ON w.`InstanceId` = h.`InstanceId`
WHERE h.`Status` IN ('Assigned', 'Pending', 'In Progress')
AND h.`Submit Date` >= $_ _from / 1000
AND h.`Submit Date` <= $_ _to / 1000
) d
WHERE d.rn = 1
ORDER BY
d.`Submit Date` ASC 
LIMIT 20

nb: you should not need select distinct when row numbering is in place - and in general avoid this when you can. Also, do yourself a favour and start using table aliases to simplify your code.