Row and column with multiple plots in VegaLite.jl

Trying to make a plot with a line and error band, and subplots in rows and columns. However, when I try this:

dat |> @vlplot(row = "sess:o", column = "PID:n") + @vlplot(:errorband, y = "rand_lb:q", y2 = "rand_ub:q", x = "trial:q", color = "block:n") + 
        @vlplot(mark = {type = "line", strokeDash = [5,3]}, x = "trial:q", y = "rand_med:q", color = "block:n")

I get this error:

Error: Bug: Channel column unimplemented for line mark
...
SyntaxError: Unexpected end of JSON input
...
Error: Bug: Channel column unimplemented for line mark

However, with a single plot mark it works:

dat |> @vlplot(:errorband, y = "rand_lb:q", y2 = "rand_ub:q", x = "trial:q", color = "block:n", row = "sess:o", column = "PID:n") 

Two plot marks but no subplotting also works:

dat |> @vlplot() + @vlplot(:errorband, y = "rand_lb:q", y2 = "rand_ub:q", x = "trial:q", color = "block:n") + 
        @vlplot(mark = {type = "line", strokeDash = [5,3]}, x = "trial:q", y = "rand_med:q", color = "block:n")

Any ideas?

Thanks!

I found the answer to this question here.