After the Windows updates from November 2020, you might be facing some issues running Bulk Inserts or working with linked servers, if you keep an open session for more than 10 hours.
Some recent changes were done on the Windows side when it comes to the way S4U (Unconstrained delegation) Kerberos tickets work.
This is a long existing SQL issue where it expects to be able to have long lived delegatable sessions without the user ever re-authenticating. This issue is normally hidden by the fact that you can renew the TGT for up to 7 days by default. However, a recent patch for PerformTicketSignatures was released and the default setting does not issue renewable tickets.
Introduced the issue with the ticket renewing process.
After installing this update on domain controllers (DCs) and read-only domain controllers (RODCs) in your environment, you might encounter Kerberos authentication and ticket renewal issues. This is caused by an issue in how CVE-2020-17049 was addressed in these updates.