A trigger is always handled in the scope of one transaction.

Cascading triggers ( as you implemented ) are handled in the scope of the same transaction.

So to get around your...

Homework, school assignment, ... try chat gpt

enable query store and get a good view onto what is going on.

check the SQLAgent.out file on your server as well as the ERRORLOG file of the SQL Server !

To figure out which CHAR s are in the string ... check this thread https://www.sqlservercentral.com/forums/topic/how-to-remove-special-chars#post-4157818

You should ask the author.

There is no benefit writing it like that, could even be a performance downside due to the potential less optimal plan due to the calculation/conversion that...

...
AND ( 
          (D.CLS LIKE '%'+ U.IND_TYPE '%'
   AND D.CLS_OPERATOR = 'IN'
   )
 ...

We use extended events to capture that data.

ref: https://www.brentozar.com/archive/2015/12/tracking-tempdb-growth-using-extended-events/

100 results is incorrect !

due to your query:

SELECT Description + ' ' FROM RawDataDescriptions FOR XML PATH(''))

it produces 1 row !

test it with the data of  Steves...

Just to get you back on track ...

How many rows do you expect from your nested select(s) ?

SELECT Description + ' ' FROM RawDataDescriptions FOR XML PATH(''))...

Have a look at Powershell module DBATools - Copy-DBALogin

Did you try to run this NOT using MERGE ?

ref: https://michaeljswart.com/2021/08/what-to-avoid-if-you-want-to-use-merge/

Did you check the "Restore ... with standby" option ?

BOL ref: RESTORE ... With Standby

Default trace holds the information you seek ! ( as long as it did not get cleaned up after a number of rolled forward for the xe files )

Have a look at Copy-DBATable of the ( free ) DBATools module in Powershell