On my system, the "Warp" button becomes a "Forbidden" glyph, and a check mark appears for no reason.
Photoshop 19.0, more recent upgrade available to me
Mac OS 10.13.1, most recent upgrade available to me.
The whole CC 2018 upgrade was forced, poorly thought out, buggy as hell, and only served some suit who want to brag they had just upgraded the whole suite. Of no value and costly in time and energy for the end user. Not pleased at all.
Something is definitely wrong there.
I would try a Preference reset (Preferences >General >Reset Preferences on Quit then restart Photoshop)
If that does not help please post a full screenshot including tools and layers panel.
Also go to System Info and click copy. Paste the info here