Here are my system information:
OS: Ubuntu 20.04 focal
Kernel: x86_64 Linux 5.4.0-105-generic
Shell: fish 3.1.0
Resolution: 3840x1200
DE: GNOME 3.36.5
WM: i3
Disk: 373G / 481G (82%)
CPU: Intel Core i7-6770HQ @ 8x 3.5GHz [70.0°C]
GPU: Mesa Intel(R) Iris(R) Pro Graphics 580 (SKL GT4)
RAM: 14398MiB / 32001MiB
And here is a little video that shows that simply clicking a region on the left does not work for me. Btw, I am using v1.1.1a. I have to click and drag but it still does not focus to the region data on the right.
Here is a little video (it's on Dropbox since I cannot embed large files in this post, I hope it works)