network disconnect error

Our local network is built entirely with Cat5e or higher-grade cables, and we are using Luminex GigaCore series network switches.
Devices such as a MIDI gateway, Sensor3, Apex10, and a Paradigm Processor are connected to this network.
Occasionally, in the Concert software, some devices appear with a gray “X” icon and cannot be controlled. When this happens, rebooting the affected device restores normal operation.
What could be the cause of this issue?

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