Did this change also affect the messages links? When I read messages starting at the Messages List heading, the links are no longer being marked as being read as I read through one post after another.
In other words, the links still show blue after I have read through several. The problem appears to be that "Next" arrow points to a "sparse" link rather than the full link as seen in the Messages list view.
eg) List view shows: https://beta.groups.io/g/main/message/29318?p=,,,50,0,0,0::created,0,,1,2,0,29318
<,> links use: https://beta.groups.io/g/main/message/29318