The ARTIK051_DONGLE_REF firmware family reports the literal string
"Nothing(SVC)" as serialNum on every unit -- non-empty, so the existing
`if not serial` checks in config_flow.py's _probe_and_validate and
coordinator.py's _run_discovery don't catch it. Two such appliances on
one install (a fridge and a freezer, each its own dongle) then collide:
config_flow gives both the same unique_id and rejects the second as
"already configured" (bug 2), and even once that's worked around,
device_serial feeds every entity's unique_id too, so the second
appliance's entities get silently dropped with "does not generate
unique IDs" log lines (bug 4).
Add _is_placeholder_serial (duplicated in both modules rather than
imported, to avoid pulling config_flow into the runtime coordinator's
import graph or vice versa for a two-line check) and treat it the same
as an empty serial: fall back to host/port.
Type detection (bug 1) and the door sensor's field-name gap (bug 3),
also reported in this issue, are already fixed via the
claude/device-support-issue-77-freezer branch, which hit the same
ARTIK051_DONGLE_REF family from a different report -- not duplicated
here.
Marc Billow
2c9fda3db1