Anyone have any idea what might be triggering this message when I launch a REPL?

Error killing transient buffer: (error Process nrepl-connection is not a subprocess)

I'm trying to understand some code in clojure-lsp . To do that, I have some test code in emacs instance A, and my checkout of a clojure-lsp server in emacs instance B. Both these emacs instances are connected to an underlying clojure-lsp server via nrepl . I can successfully redefine functions this way. What I would like to be able to do, is using cider-debug-defun-at-point, to see the calls to the functions as they happen. But if I try to invoke that I get errors to the tune of:

clojure.lang.ExceptionInfo: null
#:clojure.error{:phase :read-source}
 at clojure.main$repl$read_eval_print__9110$fn__9111.invoke (main.clj:433)
    clojure.main$repl$read_eval_print__9110.invoke (main.clj:432)
    clojure.main$repl$fn__9119.invoke (main.clj:458)
    clojure.main$repl.invokeStatic (main.clj:458)
    clojure.main$repl.doInvoke (main.clj:368)
    clojure.lang.RestFn.invoke (RestFn.java:1523)
    nrepl.middleware.interruptible_eval$evaluate.invokeStatic (interruptible_eval.clj:84)
    nrepl.middleware.interruptible_eval$evaluate.invoke (interruptible_eval.clj:56)
    nrepl.middleware.interruptible_eval$interruptible_eval$fn__980$fn__984.invoke (interruptible_eval.clj:152)
    clojure.lang.AFn.run (AFn.java:22)
    nrepl.middleware.session$session_exec$main_loop__1048$fn__1052.invoke (session.clj:202)
    nrepl.middleware.session$session_exec$main_loop__1048.invoke (session.clj:201)
    clojure.lang.AFn.run (AFn.java:22)
    java.lang.Thread.run (Thread.java:832)
Caused by: clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: No reader function for tag dbg