I installed Junos 18.3R3.4 on an EX2300 switch. I also updated JWeb to 18.2A1. The switch passes traffic without issue. The problem is that after a week or two the switch itself cannot be contacted. JWeb doesn't work. SSH doesn't work. I cannot ping the switch's IP address. But devices connected to the switch are still communicating to the rest of the network fine.
If I reboot the switch, I can connect to it again. However this will go away after a week or two.