I am having the same problem... can't edit labels. I checked my video driver and it's over a year old. I installed a new driver and it made no difference. I can select and edit every other item. I am also using Chief X9 Build 19.3.1 8x64.
Intel HD Graphics 4600 in a laptop driving a 4k External monitor. I have had this same setup for over a year with no problems until now. In fact, I edited the window labels just a couple of weeks back... and now the client wants me to switch back to the previous set of windows and I can't change the labels...
BTW, it's all labels, windows, doors cabinets, etc.
EDIT: Now when I try to edit stairs most of the items are greyed out and I can't select them... Breaklines, line styles, and half a dozen others.
