$config['snmp']['timeout'] = 5; # timeout in seconds
$config['snmp']['retries'] = 10; # how many times to retry the query
$config['snmp']['exec_timeout'] = 1200; # execution time limit in seconds
Just to add that I’m seeing the same issue in version 22.3.0 - not sure when or with what version the problem began as I haven’t been into that settings page for a long time.
To those having this issue, configuring the timeout in config.php using $config['snmp']['timeout'] = 5 still works for SNMP v3, which can be confirmed by looking at the output of a capture debug session where you can see the correct command line option being provided to snmpget.
It appears to only be a bug in the GUI display of this setting.