Hi all,
After spent a lot of time, finally, I saw that the issue has been corrected into the recent versions
Just after downloading and installing the last version (grafana-8.0.2.windows-amd64.msi), all is good, from now 
Hello @fitzterra
Were you able to fix this issue about converting the Unix timestamp to date?
This worked for me, the key insight which was not mentioned was that Value options → Show should be set to “All values” instead of “Calculate”. This way, the non-numeric values exist too, and ${__cell_0} actually accesses something