I used the Update server function in TCA and clicked on latest stable and the server refused to come back up after downloading the .jar. I instead replaced the minecraft_server.jar with one that i generated with my client. Still the same. Server refused to start or it will say running with PID 0 and give me query failed alerts.
Generated a new minecraft_server.jar on version 1.16.5 from my client and FTP in and replaced the file and it works normally. This is with a default install of TCAdmin so its the CFG that came with it.