I tried to open the extended events file but it didn't work. What were the wait statistics?

It looks like the issue is somewhere around your disks. Is this networked storage or local? Is it virtual? It looks like you're hitting some kind of spin-up delay on...

Instead of rolling your own scripts, why not look at some of the free scripts out there that do this work like Minion Backup. They'll be much more efficient.

I would focus on the wait statistics. You can capture these using extended events. Here's an article from Paul Randal. There's something blocking the process. It's hard to...

While you can't put referential constraints on the memory optimized table, you can JOIN it in a query. If there's a table that you're referencing, just run a DELETE with...

Something is up.

I don't have this in production on any of my servers, however, I test it and demo it regularly. The memory optimized tables have almost always...

The second query has an additional WHERE clause that could be affecting the output. Validate that against the first query.