Newly deployed Robot is listed in IM, but cannot be discovered in OC.w1040s01 is present in IM but it isn't in OC inventory. Customer deleted that robot from the hub in IM and cleared niscache for the Robot server - after which the robot showed up again in IM, but not in OC.
Release : 20.3
Component : UIM - OPERATOR CONSOLE
Also use this link to clear niscache to eliminate any probe data corruption.
If you see the the Robot on OC but get error message like "<deviceName> needs a Robot", please follow this Techdocs to re-deploy a Robot on the server.
Make sure all the 20.3 patches and HotFixes are installed on your UIM/Robots.
After following the above steps - new Robots having issue was listed under OC Inventory, and could see metrics for that specific Robot on OC.