NWK_NO_ROUTE on all groupcast commands with Dongle-PP10 (CC2674P10)

What happened?

After migrating from a SONOFF ZBDongle-P (CC2652P) to a SONOFF Dongle-PP10 (CC2674P10), all groupcast commands fail with NWK_NO_ROUTE (0xcd), while unicast commands to the exact same devices work normally.
The same network worked without issues on the CC2652P, including groups.

What did you expect to happen?

Groupcast commands should be delivered as they were with the previous coordinator.

How to reproduce it (minimal and precise)

1. Migrate a working network from CC2652P to CC2674P10
2. Create a group with any device
3. Send an on/off command to the existing and new groups → NWK_NO_ROUTE
4. Send the same command directly to the device → works

Zigbee2MQTT version

2.13.0

Adapter firmware version

20250321

Adapter

SONOFF Dongle-PP10 (CC2674P10)

Setup

Coordinator: SONOFF Dongle-PP10 (CC2674P10)
Firmware: Zigbee Coordinator 20250321, 115200 baud
zigbee-herdsman version: 10.8.0
Adapter: zstack
Setup: Home Assistant OS add-on, Raspberry Pi 4
Network: channel 15, 28 devices

Device database.db entry

No response

Debug log

No response

Notes

What I have already ruled out

Group ID: tested with IDs 1, 3 and 5. All fail identically.
Group size: a group containing a single mains-powered smart plug fails the same way.
Device type: tested with IKEA TRÅDFRI drivers and with two different smart plugs. Same result.
Group membership: removed and re-added members via the frontend, which re-issues Add Group Membership to the devices. No change.
Routing settling time: left running for two days. No change.
Corrupted NVRAM: based on the report in discussion #27423, I did a full recovery cycle:

1. Re-flashed coordinator firmware (same version 20250321) via the SONOFF flasher, forcing a chip erase
2. python -m zigpy_znp.tools.nvram_reset: all NV items cleared, verified
3. zigpy radio znp info confirmed NetworkNotFormed
4. zigpy radio znp restore coordinator_backup.json
5. zigpy radio znp info confirmed correct PAN ID, extended PAN ID, channel, IEEE and network key

After this the coordinator started cleanly and all devices returned without re-pairing. Unicast works. Groupcast still fails with NWK_NO_ROUTE.

Note on migration

Z2M could not commission the network onto the fresh PP10, it timed out with network commissioning timed out, most likely network with the same panId or extendedPanId already exists nearby, which is accurate since the existing network was still live. Writing the network directly to the radio with zigpy radio znp restore worked and the coordinator took over the network seamlessly. Mentioning this in case it is relevant to how the adapter is
initialised.

Start by reproducing the groupcast failure with the SONOFF Dongle-PP10, Zigbee2MQTT 2.13.0, zigbee-herdsman 10.8.0, and adapter firmware 20250321. Inspect the zstack adapter's groupcast and coordinator-initialization paths, comparing behavior with the working CC2652P setup. Done means group commands succeed for existing and newly created groups while direct commands continue to work.