No private indicator in new tab when middle mouse from normal tab

[ppzz123]

Hi,

I use a bookmark like the one below on my bookmarks bar and I open that bookmark with middle mouse which makes the bookmark open in a new private tab. Until recently the default Firefox private tab indicator would always show in that new tab but now it doesn't show the indicator anymore unless the bookmark is opened from another private tab. Even though the indicator is not shown when opening the bookmark from a normal tab, the tab does operate in private mode (I tested this).
bookmark: private:https://www.google.nl/?gws_rd=ssl

Could you make the indicator show again?

[ppzz123]

Anyone please?