This is a known deficiency in OnPlus duplicate IP monitoring, OnPlus does not currently support the announcement of the same IP address across multiple hardware interfaces. You are very likely correct that you are seeing this issue because you have a server/device that has multiple NICs bonding via ALB/LACP or other NIC teaming strategy.
Until the OnPlus product team adds a feature to OnPlus to allow for multiple 'devices' to be aggregated into the same device, I'm afraid that the only alternative is to drill into the ON100 device and to disable the Duplicate IP monitor for the time being on this network.
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