RAX80 WiFi LAN connection to Raspberry Pi computers drops - Internet connection still OK

Haven't been able to solve this issue so I wanted to ask here. I have a number of Raspberry Pi computers: a Zero, a 2B, a 3B, and a 4B. The Zero is runnng Pi-Star amateur radio software. The 2B is running FlightAware software. I have these Raspberry Pi's assigned to a static address outside the DHPC range I have set up. I am using their Mac (hardware) address in the setup. The issue. Both of these units stay connected to the Internet and do their job on that side. However, I'm running headless with SSH and VNC and need the LAN connection to control them. After a random amount of time both of these units disconnect from the LAN (even though they still work talking to the Internet). When this happens I cannot control them with either SSH or VNC. The only way I can get the connection back is to crash them by pulling the power and letting them reboot. Very dangerous on these units running on an SD card.

How can I fix this so these units will stay connected to the router and re-connect when the connection is dropped. How do you set this up on the router to do this?

Please help!

73

Dale - K0HYD