console error "Cannot add item: item with id XXX already exists" with subs graph view

[evilsneer]

when subs graph is shown only

[Error] Error thrown from trace cb (4) {ns: null, name: "re-frisk-trace", fqn: "re-frisk-trace", _hash: 912949928, cljs$lang$protocol_mask$partition0$: 2153775105, …} "while storing" {meta: null, cnt: 54, shift: 5, root: Object, tail: Array, …} Error: Cannot add item: item with id rx201 already exists — 127.0.0.1:61:141619 error (anonymous function) (cljs.core.js:13306) (anonymous function) (cljs.core.js:13288) (anonymous function) (cljs.core.js:13276) (anonymous function) (cljs.core.js:13264) (anonymous function) (cljs.core.js:13252) (anonymous function) (cljs.core.js:13534) (anonymous function) (re_frame.loggers.js:37) re_frame$trace$tracing_cb_debounced (re_frame.trace.js:111) (anonymous function) (goog.functions.functions.js:156)

unfortunately, I didn't find which special type of sub causes this