Help debugging R source code block output problem with :session

[Dylan Schwilk <dylan@schwilk.org>]

I returned to an org file this week and found that I am getting 
some strange source code block output for R code when I use the 
:session header. I have been able to duplicate this with a minimal 
init file. I strongly suspect it is some problem at my end but 
perhaps folks here can help me know here to look? It occurs with a 
minimal emacs initialization.

First, here is a small org file example of the problem. In the 
second results block the ">" appears to be treated as a prompt 
line to strip from output but only when a session is started. This 
happens with any ">" in output when the :session header occurs. 
the problem is dramatic when printing tibbles where the column 
modes are enclosed in angle brackets.

test.org
>>>
** Test org babel R output prompt problem
#+begin_src R :results output
print("<X> <Y> <!>")
print("one <two> three")
print("end")
#+end_src

#+RESULTS:
: [1] "<X> <Y> <!>"
: [1] "one <two> three"
: [1] "end"

#+begin_src R :results output :session "NEW"
print("<X> <Y> <!>")
print("one <two> three")
print("end")
#+end_src

#+RESULTS:
: [1] "<
: <
: <!>"
: [1] "one <
: three"
: [1] "end"
<<<

The second block produces the bad output. This occurs with a 
minimal setup.
I start emacs with
> emacs -Q -l "~/debugorg.el"

where debugorg.el is:

>>
require 'package)
add-to-list 'package-archives '("melpa" . 
"https://melpa.org/packages/") t)
add-to-list 'package-archives '("org" . 
"https://orgmode.org/elpa/") t)
package-initialize)

require 'ess-site)

(org-babel-do-load-languages
 'org-babel-load-languages
 '((R . t)))
<<

emacs version 26.3
org-mode version 9.3.7
ess version 18.10.3snapshot

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