After trying the preview for a short while, I encountered the following issues:
The new context menu for blueprints showing only the variables of another blueprint (instead of the refered one I dragged the pin from)
The old context menu for blueprints missing vital elements unless context sensitive is turned off (mainly the “get” nodes are missing)
UMG Grid Panel contents automatically rearranging themselves when compiling the widget blueprint
UMG String Combo Boxes not having font style options
UMG Copy and Paste not keeping the size of the element
UMG Grid Snap causing a lot of unprecise values
UMG elements not changing the cursor
UMG elements being able to get lost when trying to move them from one parent to another (happened with Grid Panels)
Control rotation stopping when the cursor hits the border of the window, even if the mouse cursor is hidden (might be a problem with my settings/blueprint but I couldn’t find the cause)
I can confirm has been occurring since all the way back to 4.2 (probably earlier), however it can be fixed. Go into Editor Preferences, under the Play section check the box for “window gets mouse control” (can’t remember the exact name, but something like that). fixed the for me back in 4.2 / 4.3, if it still doesn’t work then it must be new to 4.5.
I always enable the “window gets mouse control” option. But time it doesn’t seem to fix it. In a project I converted from 4.4 it works. It’s a simple hold RMB to enable movement and hide cursor function I created.
Here are the values before and after dragging with a high snap rate enabled: