Unfortunately there's very little activity against this table shown in the stats -- no more than 5 days' worth of activity.  Either SQL was restarted or a change was made...

Was the first result set empty??!

Not nearly enough to go on to analyze indexes.

If you'll run this script and post the two results from it, we can go further from there.  PRIOR to running, be...

SELECT 
  p.name AS [Plan], --<<--
--everything else same as before--

I would think you'd need to just do this:

...
BEGIN TRY
IF @object NOT IN ('TableA', 'TableB') --<<--
BEGIN --<<--
SET @subject = @@SERVERNAME + N' : ' + @event +...

Are you partitioning the table solely to improve SELECT performance?

How is the table clustered?  That is, what is the clustered index on the table now.  If the clus index starts...

DECLARE @time_to_stop_running time
SET @time_to_stop_running = '4:30PM'

WHILE 1 = 1
BEGIN
    SELECT <column(s)>
    FROM dbo.<your_error_table>
    WHERE ...
   ...

The business I'm at certainly doesn't require more than 200 gender "types."  Neither does yours I'm sure, nor anyone else's at this point (I guess some ultra-woke colleges...

Thank you all.

And as for space, if we have 100GB of data, then we have a 100GB of data. But I'd rather have 90GB data if...

Thank you all.

And as for space, if we have 100GB of data, then we have a 100GB of data. But I'd rather have 90GB data if that simply...

SELECT Student_ID
FROM dbo.table_name
GROUP BY Student_ID
HAVING MAX(CASE WHEN Student_Status = '2' THEN 1 ELSE 0 END) = 1 AND
    MAX(CASE WHEN Student_Status <> '2' THEN...

If you're that worried about space, you could just a minutes displacement from Jan 01, 2023.  So, midnight on that date would be 0.  2PM would be 14*60, etc..  Not...

SELECT Student_ID
FROM dbo.table_name
GROUP BY Student_ID
HAVING MAX(CASE WHEN Student_Status = '2' THEN 1 ELSE 0 END) = 1 AND
    MAX(CASE WHEN Student_Status <> '2' THEN 1 ELSE...

Temp tables should work, but for best performance be sure to create a unique clustered index on the temp tables to aid in the subsequent joins.  You'll want to create...

From the nature of some of the code, it looks like all parameters are being passed as NVARCHAR(4000).

It doesn't matter how well code may be written, that generally means...