SUMMARY I have installed 5.18.2 version from backports ppa (4:5.18.2-0ubuntu1~ubuntu19.10~ppa1). On my machine this applet doesn't work (It doesn't show any data, everything is 0 (cpu/ram/swap)). My hardware: AMD Ryzen 9 3900X 12-Core Processor 64GB RAM memory DDR4
The version 4:5.18.3-0ubuntu1~ubuntu19.10~ppa1 fixed this issue.