Only One display is working | Display not working | One monitor working only
1. If you have at least 1 video connection from each computer then using the Mode 2 feature (each computer on each monitor) you can test the KVMs output to the monitors. Both displays should work when Mode 2 is active. This confirms the KVM output is working fine.
2. If you have only one monitor working, its likely either you're missing the second video connection or the dock/adapter you're using is incompatible.
Even if the adapter works when not connecting it on the KVM, it is possible that the adapter does not work well in KVM environment.
3. If PC 1 works good with both monitors but PC 2 does not then you can swap PC 1 over PC 2 Inputs. If PC 1 works fine on both inputs this confirms the KVM is working fine and the issue is related to PC 2. Could be the port, adapter or dock being used.