Partecipant picture not updated

Dear all,

into the partecipant list the profile's picture is not updated in MM. The App retrives all the information from Moodle except the profile picture.

In order to try it:

1) Set a user picture and open the app - > the picture is displayed into the list of partecipants.

2) Set a user picture to another student and open the app -> the picture is NOT displayed (even if you perform a pull to refresh)

Do you have the same issue?

MM 2.9

Moodle 2.8.5

Thanks and regards,
Claudio