On Windows Touch, if you open the clipboard and put the focus there, moving the pointer outside of the clipboard element without clicking, e.g. using the touchpad, makes the pointer disappear, which makes it hard to know where your next click will end up. This happens on all four browsers. If you, with the focus still in the clipboard area, closes it by clicking the movable tab, the pointer is still invisible until you activate something else. This happens with all browsers except Chrome. Possibly related to bug 6222 since closing the tab returns focus to session for Chrome, but not for other browsers. Both those problems are also present in Web Access for Edge and IE on Windows 10.
This seems to have gotten fixed with bug 5779.
Tested after vendor drop (Build 6278) on: * Windows 10 with touch (Lamina) - Firefox 70, Edge 16, IE 11 and Chrome 77 Works fine now!
The release notes looks good.