Galaxy Tab A8 fails to connect properly, while Galaxy Phone S10 works fine

[tellg]

Galaxy Tab A8 connects, but then disconnects after a burst of approx 600 "Central_0x2a208f55 Peripheral_0x2a208f55 ATT 37 Sent Read By Group Type Request, Primary Service, Handles: 0x0001..0xffff"

Galaxy S10 works fine

Bot are running the same mobile app.

I have attached 2 Wireshark capture files, one for Samsung Galaxy Tab A8, the other for Samsung Galaxy S10 

We use ncs 2.6.1 on our nRF52840 hardware

SamsungS10.pcapngsamsungA8.pcapng

[Simonr]

Hi

Ah, of course. Sorry about that. The preferred PHY is indeed only a suggestion and will be negotiated upon a connection. AFAIK there is no way to hard set the used PHY to automatically set o 1MBPS, but you can change the PHY manually after connecting to the device by going to the connection settings and changing it from there.

Best regards,

Simon

[tellg]

That doesn't work, as the peripheral sets it back to 2MBPS, due to CONFIG_BT_AUTO_PHY_UPDATE as default,

which is 'y'

Sniffer log attached try-1mbit-phy-from-nrfconnect.pcapng

[Simonr]

After a quick chat with one of our Android developers there is nothing we can do in the Android BLE library to ignore this auto PHY updates, as the Android stack will adhere to these if 2MBPS is supported.

Best regards,

Simon