"Hide sidebar" no longer force closes sidebar apps?

Not sure if this is a bug or (new) feature?

I've always used "hide sidebar" to close sidebar apps, such as Discord, from running in the background.

As of tonight(?), it seems like this is no longer the sidebar's behavior, as clicking "hide sidebar" leaves everything running in the background, with Discord pings still happening and such.

Double checked that Opera is up to date. Is this intended or part of a new update, or is there a way to get back to the previous functionality still?