Help: Issues with Cycles Displacement Map in 2.8

I don’t know how to word this one correctly . I don’t know what I’m doing wrong.
I am still not that used to 2.80 - so its a bit newbie question. I have Feb14Ver of 2.80

Earlier this week I made a simple model of a bracelet and just wanted to have words engrave on it, nothing fancy.

I have done my material setup same I do in 2.79 - but for some reason it dont work it becomes this weird blob.

To be sure I did it in 2.79 with same set up an it work, i open that file in 2.80 and it work.

Nothing really different in material setup, i am wondering there is an option or something i am not looking at in 2.80.

Thank you.

First of all connecting bump vector to height input of displacement node feels wrong. You should delete bump node. (or just connect that bump node to the principled BSDF normal input and delete displacement node. But note that both are not same thing)

Check this and make sure displacement and bump (or displacement only) is enabled.