Emacs ESS and latest julia version

I am using ESS 18.10 with some recent version of julia 1.7.0-DEV.894 (2021-04-09) and I encounter the following weird behavior.

julia> let P = 10
         P
       end

returns

let P = 10
  C-c C-c

With a multiline let form, the first line is evaluated, returned then the repl hangs. Other multilines expressions do not exhibit the same behavior.

julia> a = 3
       b = 2
       a+b

returns

a = 3
3

julia>        b = 2
2

julia>        a+b
5

Is there a quick fix? Does julia 1.6 have the same problem? I switched directly from 1.1 to 1.7.