"Read" button does not refresh the wave
Under the list of participants in a wave, there is a list of buttons. One is for "mark as unread all blips of the wave", while another is for marking them as "read".
When pressing the "unread" button it does show all blips as green (unread) and the number of unread blips in the inbox list of waves (e.g. 8).
However, when pressing the "read" button afterwards, it does not show all blips as grey (read). It does though show the proper number of unread blips in the inbox list of waves (e.g. no number, as everything is read). This is just a lack of refresh, because jumping to another wave and coming back shows properly all blips as read.