Hello, thank you for elaborate reply. I discovered that this happens only when cljs code has compilation errors, then in Calva a have only clj shell.
Now before jack-in in Calva I run `lein fig:build` in shell to ensure that it has no errors and compiles, then I open Calva and run jack-in sequence, and all works fine, I get combined shell clj/cljs. Don't know why but vs-code stays silent about any cljs compilation errors while jack-in.