Modbus poll queueing

I have a ventilation unit that runs modbus RTU. And I use a modbus RTU to modbus TCP bridge to interface with my HA
http://www.hi-flying.com/rs232-rs485-rs422-to-wifi-serial-server
The RTU to TCP bridge runs into problem when HA tries to poll all my sensors (8 of them) at the same time. As a result, some of the HA polling requests are dropped and returns error. Over a period of a week or 2, the bridge will eventually crash and require a power cycle.

Is that a way to better handle polling request from HA? I tried scan_interval but HA still send all its request at the same time