Shankar,
In what region are you operating?
A assume the slow device that is restarted is the Conduit and not the lora nodes.
If you using EU868 then then the duty-cycle is also a factor in scheduling downlinks. In the latest versions of AEP you could try to disable the duty-cycle as a test to see if behavior changes. Also the duty-cycle is implemented as a sliding window, time-on-air starts at 0 and is accumulated until a transmission uses it.
CRC errors can be caused by environment or other devices (including distant LORA devices) using the ISM band.
Multipath effects and reflections may also appear on adjacent channels when devices are used in close proximity to the gateway.