If you force delete, you have to perform a general exclusion on the device to clear the old information from it, and then you should be able to re-add it, but it will re-add with a different network ID so you will have to redo any smartapp or core piston or routine that used it. The alternative is to use the Z wave replace utility, which will reassign the same network ID when you add the device back in, so that way you don’t have to change any of your smart apps.
Here’s how to do the general exclusion:
And here’s how to do the replace. ( note that the replace only works with Z wave devices, not zigbee).
But you can only do the replace if you haven’t deleted the device yet. Once you’ve deleted it, your only option is to do the general exclude and then add it as a new device