Describe the problem
When a link between two routers is down, it should present a black line (0 bps), but it is presenting a value like a query as "Last Not Null value".
To Reproduce
Create a link that has traffic and then shutdown the interface or empty the utilization to have 0 bps in it.
Expected behavior
When the link between two routers is down, it should present a black line (0 bps).
Describe the problem When a link between two routers is down, it should present a black line (0 bps), but it is presenting a value like a query as "Last Not Null value".
To Reproduce Create a link that has traffic and then shutdown the interface or empty the utilization to have 0 bps in it.
Expected behavior When the link between two routers is down, it should present a black line (0 bps).
Screenshots![Screenshot from 2023-03-06 16-02-27](https://user-images.githubusercontent.com/16313126/223209120-723b5549-e801-467e-a38d-f2e6f662d265.png)
VERSIONS! :