BLE conn disconnected when client send Exchange MTU Request with big MTU on nRF52832

[turbyho]

Description of defect

If the client sends an Exchange MTU Request with big MTU size (in this case 527B), the connection terminated.

Target(s) affected by this defect ?

nRF52832_xxAA

Toolchain(s) (name and version) displaying this defect ?

(GNU Arm Embedded Toolchain 9-2020-q2-update) 9.3.1 20200408 (release)

What version of Mbed-os are you using (tag or sha) ?

tested: mbed-os-6.11.0 - mbed-os-6.16.0

What version(s) of tools are you using. List all that apply (E.g. mbed-cli)

mbed

How is this defect reproduced ?

Use simple gatt server with ADV + some service.

Open connection and start reading some characteristic by "web bluetooth" on Chrome / MacOS 13.1 (ARM). In this case, the client requests MTU 527B and connection fail on timeout. There missing MTU Response. Same code on nRF52840 works ok, server return correct MTU Response with 23B.

The web client on which the error also occurs. So it is possible to use it to reproduce the error.

[mbedmain]

@turbyho thank you for raising this issue.Please take a look at the following comments:

Could you add some more detail to the description? A good description should be at least 25 words.

NOTE: If there are fields which are not applicable then please just add 'n/a' or 'None'. This indicates to us that at least all the fields have been considered.
Please update the issue header with the missing information.

[turbyho]

is solved by correct ble cfg for ios/macos.