Switching accounts does location.reload(), which preserves history.state — so the new
account re-mounted the Messages module from the previous account's _sub sub-view, whose
partnerId belongs to the OLD identity (often the new account's own id → an empty
self-thread). Symptom: after switching to the recipient you land on a blank thread and
the just-received message never shows (F5 keeps history.state); only going back to the
list and reopening the real conversation works.
Fix: (1) strip _sub/_ov from history.state before the switch reload so the new account
starts at the module root; (2) guard Messages so a thread view with partnerId === meId
falls back to the conversation list (can't message yourself).
peter
47860337a1