Hi Mike,
Most likely you are hitting a timeout issue because the server response did not arrive within expected period of time.
There are three types of timeouts in MySQL ODBC Driver:
1. Login timeout. This timeout can be set using SQLSetConnectAttr() ODBC function.
This timeout corresponds to the number of seconds to wait for a login request
to be completed before returning an error.
Please check the following online manual:
https://docs.microsoft.com/en-us/sql/odbc/reference/syntax/sqlsetconnectattr-function?view=sql-server-ver15
2. Read timeout. This timeout can be set through the connection string
"...;READTIMEOUT=number_of_seconds;"
The option is not available through the GUI Dialog.
READTIMEOUT is the timeout in seconds for each attempt to read from the server.
There are retries if necessary, so the total effective timeout value is three times the option value.
You can set the value so that a lost connection can be detected earlier than the TCP/IP
Close_Wait_Timeout value of 10 minutes.
3. Write timeout. This timeout can be set through the connection string
"...;WRITETIMEOUT=number_of_seconds;"
The option is not available through the GUI Dialog.
The timeout in seconds for each attempt to write to the server.
There is a retry if necessary, so the total effective timeout value is two times the option value.
I hope this helps.