Designer Mouse(1679) on Android 11 occurred supervisionTO(connection fail)

Question

I try to pair the Designer Mouse(1679) on Android 11, but the Designer Mouse may be disconnected in some scenarios.

Issued scenario:
[1] I first paired two LE RCUs on Android 11 and then paired the Designer Mouse and a superversionTO occurred on the designer mouse.
The recurrence rate of this issue is very high.
In addition, [2]if I paired the Designer Mouse first and then paired two LE RCUs on Android 11, the pairing of designer mouse will be successful.

Designer Mouse superversionTO occurs because the Android 11 will initiate connection update procedure after encryption is started.
The instant in connect_update_ind specifies that both should adopt new connection parameters in the 10th instant in the future.
But the designer mouse will no longer respond to the Android 11 after the 9th instant, and superversionTO after 2 seconds.

I compare the Designer Mouse is the first paired[2] log to the third paired log[1]
I found that in the first paired log, the Android 11 will initiate the connection update procedure later.
Start Encryption and connection update procedure are about 600ms apart.
But in the third paired log, the Android 11 will start the connection update procedure about 100ms after starting encryption.

So I do an test, I also let the Designer Mouse be the third paired, but when the Android 11 is ready to start the connection update procedure.
I deliberately delay 500ms and then send connect_update_ind, the designer mouse can be successfully paired.

I don't understand why the Designer Mouse can't do the connection update procedure too quickly.
Or is there another reason I haven't found...