diff --git a/internal/cat/icomserial.go b/internal/cat/icomserial.go
index e2500cb..f10e01e 100644
--- a/internal/cat/icomserial.go
+++ b/internal/cat/icomserial.go
@@ -1935,12 +1935,25 @@ func (b *IcomSerial) SetIcomSplitOffset(on bool, offsetHz int64) error {
 		// yesterday's mode transmits FM into a CW pileup. 0x26 0x01 sets the
 		// unselected VFO's mode + data flag in one frame; rigs that predate
 		// 0x26 NAK it harmlessly and behave as they always did.
+		if b.curModeByte == 0 {
+			// A fresh session may not have read the mode yet — ask, or the copy
+			// below would send mode 0 (LSB) whatever the main is on.
+			if m, ok := b.readMode(); ok {
+				b.curModeByte = m
+			}
+		}
 		if b.curModeByte != 0 {
 			dataByte := byte(0)
 			if got := b.readDataMode(); got {
 				dataByte = 1
 			}
-			_ = b.exec(civ.CmdModeDataFil, 0x01, b.curModeByte, dataByte, 0x01)
+			// Logged, not discarded: the first version swallowed the error and a
+			// real 7760's sub VFO kept yesterday's mode with nothing to show why.
+			if err := b.exec(civ.CmdModeDataFil, 0x01, b.curModeByte, dataByte, 0x01); err != nil {
+				applog.Printf("icom: split mode-align (26 01 %02X %d) refused: %v", b.curModeByte, dataByte, err)
+			} else {
+				applog.Printf("icom: split mode-align OK (26 01 %02X %d)", b.curModeByte, dataByte)
+			}
 		}
 	}
 	if err := b.exec(civ.CmdSplit, boolByte(on)); err != nil {