With the toolbars disabled (i.e. View->Toolbars->Main unchecked), a smaller selection icons appear on the line at the top of the folder view (i.e. the line that says the name of the folder, like "Mailbox (##)").

In GroupWise 2014R2 this worked fine; I'm not exactly sure when this feature was introduced, but those with smaller and/or wider displays like it as it saves screen space.

In GroupWise 18SP1 however the icons disappear every time the screen refreshes until you mouse-over them. (I can't say whether this happened with the original GW 18 client, as I only deployed it on my own computer and I use the traditional toolbars so I wouldn't have noticed this issue)

I've re-produced this problem on several different computers, most running windows 10 but also on the one remaining Windows 7 box we have running GroupWise.