They used to be there. No idea if can add. Beyond this volunteers scope of expertise. You can try the linux forums as seems someone wanted that at one time. https://ubuntuforums.org/showthread.php?t=2325112

Please let us know if this solved your issue or if need further assistance.

You can try a different theme in your Linux distribution in case you currently usea theme that isn't GTK3.4+ compatible.

I don't see that changing the theme is much of a solution simply because, as I don't see any way of listing a themes details, I'd have to install all the themes in turn hoping that it addresses the issue. Maybe editing the theme would be a solution, but I don't see any way of doing that. Now if one of the theme creators would create a modified default 54 theme with the arrows put back, that would be good :)