Two instances of node red active

[CHLINDE]

Hello!

I got a raspberry pi for maintainance. To connect to the dashboard, I enter http://172.16.30.21: 1880 into firefox. Everything seems to be fine.
But when I enter "http://172.16.30.21" without the port value, I reach another node-red UI. When I try to reach the flows of this UI it is not possible.
How can I check, which instances of node red are currenly running and how can switch of the UI of the wrong page?

Thank you

[TotallyInformation]

Do you have a web server running such as NGINX, Caddy or Apache for example? Being able to access the UI implies you are using port 80 and typically you have to be running as root or from systemd with some extra configuration as port 80 is a privileged port. But web servers like those mentioned can act as "reverse proxies" and so present data over a different port - effectively do a port translation.

Try using a BASH terminal prompt and run ps -ef | grep node to see what instances of node.js and node-red are running.

In this example, you can see that node-red is running as process ID 25480 having been instigated by process ID 1 (systemd).