I'm running WSJT-X 2.4.0 on a Dell XPS-13 laptop, running Windows 10 Home 19.09 connected to an Elecraft K4 in DATA mode. Settings | Radio | Split Operation = Rig in order to position the transmit tone in the passband. I believe SPLIT was working a few WSJT-X releases ago. Now, when I double-click a CQ in the left-hand window, it puts the K4 VFO B into DATA-R mode ("reverse") and the K4 complains on its screen that that type of split mode isn't allowed. I suppose it also returns an error to WSJT-X because it then refrains from using SPLIT mode. Instead, it transmits on VFO A which remains at the bottom of the band. I'm pretty sure this was introduced in a recent release of WSJT-X. Any thoughts?