The uBITX display frequency in CWU/CWL is the RX frequency not the TX frequency. The norm in CW on most commercial rigs is to always display the TX frequency.
You can however set the RX offset. It seems that yours must be 1.5 Khz which is a lot. Typically it would be something in the range of 500 to 800 Hz.
There is a related issue which I have reported and that is that changing CW modes is "broken". When switching back and
forth between CWU/CWL modes the TX frequency changes and the RX frequency does not which is wrong. This means that
if you properly tune in a CW station (RX tone matches your offset) on CWU and switch to CWL the other station is no longer audible and
he can't hear you. It should be possible to switch back and forth between CWU and CWL and still maintain contact.
See message #51983 for more details.