I have confirmed the same thing in the CEC firmware V1.08. The uBITX display frequency is the RX frequency not the TX frequency.
I will now explain why this is a problem.
This is not theoretical .. I tried this with my Flex-1500 with both rigs side-by-side, TXing into dummy loads.
My Flex is transmitting on 7.030 Mhz CWU exactly (dial frequency BTW) using a 700 Hz RX offset. The uBITX is on CWU has a 700 Hz sidetone set (ie offset) then
the dial on the uBITX needs to be at 7.029.300 Mhz so that it is receiving a the Flex with a 700hz audio tone. Both stations can hear each other with a 700 Hz tone. This confirms that the uBITX dial frequency is the receive frequency not its transmit frequency. I can also see and hear that the uBITX is transmitting on
7.030 Mhz with this dial setting.
Now I switch the Flex to CWL without changing frequency. I leave the uBitx on the same frequency (7.029.300 Mhz) and still on CWU. Both stations can still hear each other with a 700 Hz tone. Changing modes on the Flex left the TX (dial) frequency the same and only moved the RX frequency of the Flex to the other sideband (ie. the Flex RX frequency switches from 7.029.300 Mhz to 7.030.700 Mhz).
I put back Flex back on CWU without changing frequency (ie. dial still shows 7.030 Mhz). Now switch I the uBITX from CWU to CWL. The dial frequency on
the uBITX still shows 7.029.300 Mhz on the dial but it is now transmitting at 7.028.600 Mhz and is inaudible to the Flex which is still listening at 7.029.300 Mhz !
With any rig in CW mode, when you have a station tuned in and are listening you should be able to switch from CWL to CWU at at any time and without
retuning and you should be able to hear the other station and he should still be able to hear you. The whole idea of switching sidebands in CW mode is to
be to use it as a means of avoiding adjacent noise. Sometimes switching from CWU to CWL will allow you to avoid QRM.
That is only possible if the uBITX TX frequency remains fixed on CW sideband changes (CWU/CWL) and the RX frequency changes according to the sideband selected and the configured offset.
So that means that the display frequency since it is fixed, must be the TX frequency. The RX frequency should change on switching from CWU to CWL based on a minus or plus offset from the TX frequency.