--- comint.el.orig	2021-02-06 16:55:28.000000000 -0800
+++ comint.el	2021-02-06 16:57:24.000000000 -0800
@@ -1922,7 +1922,7 @@
             ;; Wait for all input to be echoed:
             (while (and (> (+ comint-last-input-end echo-len)
                            (point-max))
-                        (accept-process-output proc)
+                        (accept-process-output proc 1)
                         (zerop
                          (compare-buffer-substrings
                           nil comint-last-input-start