We are using Milesight UG65, end device is enviroment monitoring system AM319. When we use onboard NS the uplink and downlink are working as expected, we get frames on time intervals set on the end devices. when we configure the gateway to packet forwarding and use chirpstack as the NS we only get part of messages and they are all delayed. anyone know why?
We use US915 equipment
we have all endpoing successfully joined and reporting at least once but then problems start and the endpoints are starting to delay until uplink arrive once in few days. all endpoints are connected to energy and working in class c.
If the spreadfactor of the AM319 is greater than 10, packets will be broken up and sounds a little like what is happening here. I’m pretty new though so take what I say with a grain of salt 
Well the solution was the sub-band configuration,on the Milesight gateway the frequencies are marked 0-7 but actually they work with sub-band 2 that is 8-15, so we had the chirpstak network server with the configuration of sub-band 1. the AM319 had a configuration of spreadfactor SF7-DR3 but with ADR and at the first download the mask was changed and SF was changed. as soon as we found out that the sub-band is wrong everything started working as expected.
Glad it was resolved!