Your cDAQ may not be able to be seen because it is TSN (Time Sensitive Network) enabled. TSN uses the Rapid Spanning Tree Protocol (RSTP) to create a loopless network, which is not compatible with some network settings.
From DAQmx 19.5 release
the users can disable RSTP for the TSN chassis, complete instructions are available in Enabling and Disabling RSTP on FieldDAQ and CompactDAQ 9185 and 9189 Devices
This feature is not present on previous releases of NI-DAQmx. You may be able to configure your network devices differently to enable communication; for example, disabling Bridge Protocol Data Units (BPDU) guard will enable RSTP devices to work correctly. If it is not possible to configure your network differently, you could consider non-TSN cDAQ chassis such as the cDAQ-9184 or cDAQ-9188.