What were the changes in 5.12.85?

Can you please provide more details as to what was changed in this version? Whatever they were, some of the CSS I had added to the related posts layout (spacing and fonts) is no longer applied (did you change any element class or id names, perhaps?) and also stopped the Zoom+ Icons Link + Opacity setting from working. I’ve reverted to the previous version and it all works as before but it would be really helpful to have more details of what was changed in the latest version so that I can edit my CSS to reflect the changes you have made.
Many thanks for your help.