SQL Server – Intermittent connection problems with Windows authentication

I have a strange. I have been experiencing occasional login errors via Windows authentication for two weeks and the network team and I have not yet found a solution.

I'm running SQL 2016 on a physical server running Windows Server 2012 R2.

Meanwhile, I asked the users to wait five minutes and try to reconnect. If the user waits five minutes, he can (most of the time) connect. I've had cases where I could not login for 15 minutes and then my next connection attempt works.

In the SQL error log, I see entries like this:

Connection failed. The connection comes from an untrusted domain and can not be used.
with Windows authentication. [CLIENT: XX.XX.XXX.XXX] Error: 18452,
Severity: 14, state: 1.

The SSPI link failed with error code 0x80090311, state 14 while
establish a connection with the integrated security; the connection has
been closed. Reason: AcceptSecurityContext failed. The Windows error
code indicates the cause of the failure. No authority could be contacted
for authentication. [CLIENT: XX.XX.XXX.XXX] Error: 17806, severity:
20, Condition: 14.

On the server, I see this:

An account failed to connect.

Subject: Security ID: NULL SID Account Name: – Account Domain: –
Login ID: 0x0

Connection type: 3

Account for which Logon Failed: Security ID: NULL SID Account
Name: A domain of user account: A domain

Failure Information: Reason for Failure: An error occurred while logging on.
Status: 0xC000005E Sub-status: 0x0

Process information: Caller process ID: 0x0 Caller process name: –

Network Information: Workstation Name: A computer source network
Address: – Source port: –

Detailed authentication information: Login process: NtLmSsp
Authentication package: NTLM Transited Services: – Package name
(NTLM only): – Key length: 0

Any ideas on what might cause (sometimes) connection failures like this?