Dashboards for viewers not available

Hello Experts,
We have a board which is connected to a dashboard.
The board has many users registered as members, with permissions to change items on the board.
On our dashboard, we have a select few who are not “members”, rather they are viewers on the same company domain. Please note that the dashboard is set on a private mode, accessible only to a few with invitations or manually subscribed by the admin.

Till day before yesterday, the viewers were able to see the dashboard, however, since today morning, all of the viewers are locked out of the dashboard, with a message that they need to “ask for permissions”.
The viewers are also subscribed to the main board as viewers and also to the dashboard as viewers.
What am I missing here?
Has there been a change in the permission matrix which I need to update.
Please help