What happened?
Device: SONOFF MINI-ZB2GS (MINI DUO, with-neutral variant), firmware 1.0.7 (build 4103, date code 20251231 — latest available in zigbee-OTA).
Both channels are wired to latched wall switches on S1/S2, with external_trigger_mode_l1 = edge and external_trigger_mode_l2 = edge, detach_relay disabled (relays controlled locally by the device).
When both wall switches are flipped at the same moment, only ONE relay toggles — the other input edge is silently dropped. When the switches are flipped sequentially (even with a small delay), both relays toggle correctly, every time.
This looks like a firmware-level input handling issue (shared debounce window / single input event state machine?): two near-simultaneous GPIO edges on S1 and S2 result in only one being processed. Since the relays are switched locally (detach disabled), zigbee2mqtt is not involved in the failing path — reporting this here for visibility and to reach the SONOFF firmware team (@CubeZ2mDeveloper), as MINI-ZB2GS firmware is not available via the SONOFF firmware API and 1.0.7 is the newest published build.
The same symptom class has been reported on other dual-channel relays (e.g. TuYa TS0012: https://community.home-assistant.io/t/moes-ts0012-cannot-turn-both-switches-on-at-the-same-time/833729), where it was also attributed to device firmware.
Possibly related open MINI-ZB2GS 1.0.7 issues: #32070, #32174, Koenkk/zigbee-OTA#1180.
What did you expect to happen?
Both relays toggle, regardless of whether the two external switch edges arrive simultaneously or sequentially.
How to reproduce it (minimal and precise)
- MINI-ZB2GS with both channels wired to latched wall switches (S1/S2),
external_trigger_mode = edge on both channels, detach_relay disabled.
- Turn both lights ON.
- Flip both wall switches at exactly the same moment.
- Observe: only one relay switches OFF; the other stays ON. Only a single
toggle_lX action / state report for one endpoint is seen in zigbee2mqtt.
- Flip the switches sequentially instead — both relays switch correctly.
Reproducible ~100% when the presses are truly simultaneous.
Zigbee2MQTT version
2.10.1 (zigbee-herdsman 10.0.7, zigbee-herdsman-converters 26.46.0)
Adapter firmware version
EmberZNet 8.0.2 [GA] (build 397, EZSP 14)
Adapter
EFR32-based coordinator, ember driver (TCP)
Setup
Docker (ghcr.io/koenkk/zigbee2mqtt), network adapter over TCP
Debug log
No response
What did you expect to happen?
No response
How to reproduce it (minimal and precise)
No response
Zigbee2MQTT version
2.10.1
Adapter firmware version
8.0.2 [GA] (build 397, EZSP 14)
Adapter
EFR32-based network coordinator over TCP, ember driver
Setup
Docker container (ghcr.io/koenkk/zigbee2mqtt) on Debian GNU/Linux 13, aarch64 (Linux cm3588 6.1.141 #16 SMP Thu Dec 4 14:51:28 CST 2025 aarch64 GNU/Linux)
Device database.db entry
No response
Debug log
No response
Notes
No response
What happened?
Device: SONOFF MINI-ZB2GS (MINI DUO, with-neutral variant), firmware 1.0.7 (build 4103, date code 20251231 — latest available in zigbee-OTA).
Both channels are wired to latched wall switches on S1/S2, with
external_trigger_mode_l1 = edgeandexternal_trigger_mode_l2 = edge,detach_relaydisabled (relays controlled locally by the device).When both wall switches are flipped at the same moment, only ONE relay toggles — the other input edge is silently dropped. When the switches are flipped sequentially (even with a small delay), both relays toggle correctly, every time.
This looks like a firmware-level input handling issue (shared debounce window / single input event state machine?): two near-simultaneous GPIO edges on S1 and S2 result in only one being processed. Since the relays are switched locally (detach disabled), zigbee2mqtt is not involved in the failing path — reporting this here for visibility and to reach the SONOFF firmware team (@CubeZ2mDeveloper), as MINI-ZB2GS firmware is not available via the SONOFF firmware API and 1.0.7 is the newest published build.
The same symptom class has been reported on other dual-channel relays (e.g. TuYa TS0012: https://community.home-assistant.io/t/moes-ts0012-cannot-turn-both-switches-on-at-the-same-time/833729), where it was also attributed to device firmware.
Possibly related open MINI-ZB2GS 1.0.7 issues: #32070, #32174, Koenkk/zigbee-OTA#1180.
What did you expect to happen?
Both relays toggle, regardless of whether the two external switch edges arrive simultaneously or sequentially.
How to reproduce it (minimal and precise)
external_trigger_mode=edgeon both channels,detach_relaydisabled.toggle_lXaction / state report for one endpoint is seen in zigbee2mqtt.Reproducible ~100% when the presses are truly simultaneous.
Zigbee2MQTT version
2.10.1 (zigbee-herdsman 10.0.7, zigbee-herdsman-converters 26.46.0)
Adapter firmware version
EmberZNet 8.0.2 [GA] (build 397, EZSP 14)
Adapter
EFR32-based coordinator, ember driver (TCP)
Setup
Docker (ghcr.io/koenkk/zigbee2mqtt), network adapter over TCP
Debug log
No response
What did you expect to happen?
No response
How to reproduce it (minimal and precise)
No response
Zigbee2MQTT version
2.10.1
Adapter firmware version
8.0.2 [GA] (build 397, EZSP 14)
Adapter
EFR32-based network coordinator over TCP, ember driver
Setup
Docker container (ghcr.io/koenkk/zigbee2mqtt) on Debian GNU/Linux 13, aarch64 (Linux cm3588 6.1.141 #16 SMP Thu Dec 4 14:51:28 CST 2025 aarch64 GNU/Linux)
Device
database.dbentryNo response
Debug log
No response
Notes
No response