Limitation of Uplink data to lora gateway

Hi everyone,
Using lora RFM95x radio module to send data to application server by uplink mode.is there any limitations to send the uplink data to app server.rightway processing data for every 1min interval in a day.
Here is my observation,
Considerable packet loss and my sensor gateway stopped working for after some times randomly .
No of sensor gateway (bridge):10 nos.
BW:125KHz
SF:SF7
Tr power:14 dbm
Operating region :USA 915 MHZ
Payload size:38 bytes
Mode:uplink

While stopping to work,
if I give small vibration or movement to my sensor gateway ,it’s started to push data to app server.
I am bit confused to isolate this problem.
1)how often the sensor gateway supposed to push data to app server?? Is there any limitations
2) currently using more than 10 sensor gateways in my app project.is there any limitations in using no of sensor gateway to communicate with lora gateway.
Please anyone help me out to resolve this issues.