Why would our document numbering leap from 5 digits to 13 digits? I checked our auto generation settings and nothing has been changed that I can see. Only two new Credit Memos were added.

Someone likely overrode the document number on one of those transactions. You need to go to your settings and reset the sequence to the correct next number

I thought the same thing but opened a ticket with netsuite and found out it was a known issue. If you have advanced numbering on and import adjacent transactions it can mess up all the numbering.

It was an override during implementation. We've fixed it.