That explorer is on the wrong chain
One of the new explorers -
https://chainz.cryptoid.info/lux/Also please only use the following nodes in your conf file as they are all v4 - none of the previous ones are correct with 28666 as the port - the new v4 uses 26868 as the port
addnode=73.15.255.41:26868
addnode=88.88.9.196:26868
addnode=5.189.142.181:26868
addnode=87.121.21.87:26868
addnode=185.80.155.169:26868
addnode=24.8.183.131:26868
addnode=219.75.75.71:26868
addnode=217.174.57.125:26868
addnode=81.108.220.210:26868
addnode=95.31.27.38:26868
addnode=5.166.86.151:26868
addnode=18.96.7.166:26868
addnode=108.35.209.233:26868
addnode=43.255.112.21:26868
addnode=103.252.219.154:26868
addnode=176.32.5.50:26868
addnode=45.77.44.147:26868
addnode=207.246.96.37:26868
addnode=45.76.33.22:26868
addnode=108.61.208.4:26868