Missing DFU - CONTROL characteristic in DFU mode only on Android Chrome Browser

[tomserowka]

Missing DFU - CONTROL characteristic in DFU mode only on Android Chrome Browser

Expected scenario:

Device in “normal/not DFU” mode:
DFU Service contains 1 characteristic:
“BUTTON”, UUID: 8ec90004-f315-4f60-9fb8-838830daea50

When DFU mode is enabled on the device DFU Service contains 2 characteristics:
“CONTROL”, UUID: 8ec90001-f315-4f60-9fb8-838830daea50
“PACKET”, UUID: 8ec90002-f315-4f60-9fb8-838830daea50

Chrome on Android Scenario:

Device in “normal/not DFU” mode:
DFU Service contains 1 characteristic:
“BUTTON_LESS”, UUID: 8ec90004-f315-4f60-9fb8-838830daea50

When DFU mode is enabled on the device DFU Service still contains only 1 characteristic but this time it’s:
“DFU_PACKET”, UUID: 8ec90002-f315-4f60-9fb8-838830daea50

The missing characteristic: “CONTROL”, UUID: 8ec90001-f315-4f60-9fb8-838830daea50.

ISSUE: When putting the Bluetooth device in DFU mode on Android Chrome, one of the characteristics is missing (CONTROL one), it happens only on Android Chrome. Works on all other browsers that support Web Bluetooth Api.

LOGS:

Error connecting to DFU Targ No Characteristics matching UUID 8ec90001-f315-4f60-9fb8-838830daea50 found in Service with UUID 0000fe59-0000-1000-8000-00805f9b34fb.
DFU Mode On, Getting Control and Packet Chars
found DFU service
connected to gatt server
Server Disconnected...Reconnecting
Server Disconnected...Reconnecting
sent DFU mode
enabled buttonless notifications
found buttonless characteristic
Searching Button UUID 8ec90004-f315-4f60-9fb8-838830daea50
found 1 characteristic(s)
Values for Characteristic 1 Mode false
DFU Mode Off, Getting Button Less Char
found DFU service
connected to gatt server