SDK15.3 S132 disconnect from oppo when send data

[taol]

This is my problem description, hope someone can help me.
1. The watch product shipped in mass production is found to be disconnected when using the mobile phone OPPO-k7x to send a file. No problems have been found on other phones for the time being.
2. The watch software uses SDK15.3, S132, and there are logs after connecting with the mobile phone:
nrf_ble_gatt: max_rx_octets: 251
nrf_ble_gatt: max_tx_octets: 251
nrf_ble_gatt: max_rx_time: 328 (this parameter is 2120 when other mobile phones are connected)
nrf_ble_gatt: max_tx_time: 2120
3. When the same software code and sdk_config use S112 protocol stack, it is no problem to connect OPPO-k7x.
4. The influence of hardware signals and ble_gap_conn_params has been excluded.
5. When the watch is connected to OPPO-k7x, the short data packet communication is normal, and it is disconnected when only sending large data. The reason is 0x08[BLE_HCI_CONNECTION_TIMEOUT]. The Wireshark log is:

[Simonr]

Hi

From the snippet of the sniffer log you uploaded I'm not able to see a disconnection event or this disproportionate max_rx_time you mention. Could you possibly upload a full sniffer log where we can see the disconnect, as well as a sniffer log where the application is running as expected when connected to another phone for comparison?

Also, what phones have you tested on where this works? Is it only this OPPO-k7x that causes disconnects? Can you explain a bit more on what nRF52 device you're using as well? An nRF52 Development Kit or a custom board/third party module?

Best regards,

Simon

[taol]

Thankyou for your Reply.

1. My device is NRF52832, other phones like iphone, and some android phones SAMSUNG, HUAWEI, XIAOMI, also an other OPPO-reno all works fine.

2. Sniffer log after screen show nothing but the device return advertising after 4 sec(Connection supervisory time-out (4 seconds)).

[taol]

I think my question is somewhat similar to this one:https://devzone.nordicsemi.com/f/nordic-q-a/16498/s132-v3-exchange-mtu-le-data-packet-length-extension-does-t-work ,but not sure, and don’t know how to solve it too.