Cannot toggle between channels with new VR15 TV Remote

Any TV Remote I've ever owned (including my Xfinity XR2 Remote) had a "Last" button that allowed me to return to the prior channel I was viewing, and also to toggle back and forth between those two channels.

This week I was given a new XR15 Remote (Voice controlled) by an Xfinity technician. A left-pointing white arrow on the remote is identified in the Guide as the "Back" button. When I use that button it presents me with a row of 6-8 channels to choose from, including my previously viewed channel. To go back to the previous channel I have to click on the previous channel number and then find and click on the little (and very difficult to push *)  "Enter" button.

This makes no sense to me. Is there no other way to toggle between two channels ?  

* In fact, the Power, A, B, C, D, Enter and the 4 central arrow buttons are all absurdly small and very difficult to push. Ergonomically, this is the worst TV Remote I've ever seen