I have to agree with Perry.   I would NOT risk using the results of this DR exercise to make any kind of business decision, even if the result is successful,...

And that the size of your rows in the sub-report matches the size of rows in the main report.

I'd start with having your network team analyze the traffic and see exactly what's going on.   While awaiting that response, I'd search online for any issues with the various KB...

See the details here:

https://stackoverflow.com/questions/6260688/how-do-i-use-cascade-delete-with-sql-server

My first question is WHY?   What possible benefit is there to this methodology?

The backup would certainly be smaller, and thus both backup and restore times would be shorter, but if you just move the physical file across the network, there's no reduction...

Seems likely that you have a data type issue.   What data types does MySQL support?   If they only support datetime as opposed to just a date (without time), then you...