MP50 stuck after call transfer

[af@benenden.school]

Hi,

The MP50s appear to have an issue where they get stuck after transferring a call.

To repro:
1. Answer a call with the MP50
2. Transfer the call and wait for the transfer to complete and the call end
3. Try to answer another incoming call with the MP50

Symptoms:
1. The call fails to pickup, and the caller gets sent to voicemail
2. The MP50 screen still shows the first call as ongoing and cannot be ended
3. The MP50 returns to normal after the second failed call

Workarounds:
1. Reboot the phone after transferring a call
2. Answer calls using the Teams client and then pickup the handset

This does not appear to affect "consult and transfer". Teams is on the latest version, and we've tested the MP50s straight out of the box and on the latest firmware 131.410.0.55. These have also been tested on different computers, although sometimes the symptoms change ultimately the phone gets stuck after the transfer.

One of the purposes of buying these phones is so they can be used on the reception desk with Teams, so the ability to reliably transfer calls is critical. They're

We have bought around 40 of these devices, please can anyone help?

Kind Regards,
Andrew