SQL Login timeout expired when PC Online

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1

Hi,
I have an SQL application on SQL2014. OS is Windows10. When PC is offline, the SQL application runs, but when it is online have below error
General SQL error. [Microsoft][ODBC SQL Driver]Login timeout expired
Please help. Firewall is already off

2

I don't think I can do what you have done. The only thing I can think of is that you have set the setting of the database to single user:

Set a database to single-user mode - SQL Server | Microsoft Learn