have a mn running , but after 2-3 hours connection to mn lost , anybody can help me ?

rpcallowip=127.0.0.1
rpcuser=youuuu
rpcpassword=fuuuuuu
server=1
daemon=1
listen=1
staking=0
port=9999
masternode=1
masternodeaddr=146.60.250.143:9999
masternodeprivkey=???
externalip=192.168.0.102
addnode=104.236.4.12
addnode=62.162.181.2
addnode=93.103.73.22
addnode=78.20.126.124
addnode=188.166.83.211