While trying to connect to PackeShaper, the management traffic gets delayed or dropped time to time. This causes access/login issue to the PacketShaper.
Usually the problem happens when they have multiple path between hosts and the PacketShaper, and they are on a different subnet.
It could be due to 'Return to Sender' feature. With 'Return to Sender' feature enabled, PacketShaper could send packets using MAC and port based on the 'next hop address' it learned from the previous packets. And it is helpful when ARP is not working or no proper gateway address is configured in simple network. However, in some multipath networks, it could confuse the PacketShaper and may have incorrect 'Next hop address' for some management hosts.
Disable 'Return to Sender' feature as 'sys set returnToSender 0' and reboot the PacketShaper.
Then, the problem would be resolved.
After disabling 'Return to Sender' feature, it will always send the management packets relying on the gateway address and ARP.