What does it mean if the communication (COM) indicator is orange and how to handle it?

It means communication between meter and inverter is faulty.

Following actions can be taken to fix this issue.
①Check if the connection between the meter and the inverter is correct and well.
②Ensure that used meter is compatible with Solinteg inverter.
③The communication wire between meter and CT or the grid side should be shorter than 3 meters.

If your solar system adopts master-slave parallel strategy, since the slave inverters are not necessary to be connected with the meters, it is normal that all COM indicators of slave ones will be orange.