Any website I visit to get info, example to create a web site with the JS 4.x and calcite (bootstrap based), it states:
"This project is depreciated and is not recommended for future development. It will be replaced with a newer version. Coming soon!"
That was 2 years ago. Even on geonet the last question posted on calcite was a year ago.
What is the latest, ESRI?
https://github.com/Esri/calcite-maps