Cannot add multiple custom UUIDs?

[RMV]

I have reviewed most (if not all) posts on this forum that relate to multiple vendor specific UUIDs but still see issues on my platform.

I am using nRF52832 (with minor changes unrelated to Bluetooth) and Soft Device version 6.1.1

I have two custom 128-bit UUIDs that are very close to each other but differ only in bytes 12 and 13.
I want to use one set of values of bytes 12, 13 to advertise and the other pair to scan.

First question: Is this a viable / expected use case of multiple vendor specific 128-bit UUIDs

Second question: No matter what I do, two back to back calls to sd_ble_uuid_vs_add() always return the value '2' for the UUID type.
I was expecting to see the type be set to '2' for the first call and '3' for the next one but no such luck.

What is going on here -- or am I going about this the wrong way?

This has been bothering us for over a month now, so any feedback would be appreciated.

[Jørgen Holmefjord]

Hi,

This is explained in the Note in the API documentation for sd_ble_uuid_vs_add:

Bytes 12 and 13 of the provided UUID will not be used internally, since those are always replaced by the 16-bit uuid field in ble_uuid_t.
If a UUID is already present in the BLE stack's internal table, the corresponding index will be returned in p_uuid_type along with an NRF_SUCCESS error code.

Since bytes 12 and 13 are masked out, you are adding the same base UUID twice. If the base UUID already exists in the table, the corresponding index will be returned.

Best regards,
Jørgen

[RMV]

I have already read the note and do understand it.
I just wanted to confirm that my understanding was correct.

In this case, what is the best option to switch between broadcasting and scanning "with the same base UUID but different bytes 12 and 13"? Is that even allowed/possible with Nordic nRF52?