You do have the correct firmware, as I was one of maybe the first half-dozen test rats [with appreciation to Dr Lee] at the release time.
11.055.500 is as good place to begin. Mine's dialed in at around 11.054.850 so there is going to be a little wiggle room. I'm going to offer a few points that may or may not be in the virtual instruction book; those that are, bear repeating. Please do them:
1. After making any change in the BFO number, use the mike PTTto store it and...
2.... turn the radio power off for ten seconds or more.
3. Obey rule #2 every time, even if you land on the same BFO number again.
4. Subsequent to a BFO change and power-off cycling, go and tune in a moderate-level QSO. Not dial-bending but not some SOTA group 3 continents away, either. Then, select the opposite side and tune a little, see if you can manage to tune the same qso to a listenable quality on the wrong sideband; if you can do that, you need to tune again and go another xx.xxx.100 or more away. I can't tell you which way, but set it and cycle off the power again. If it's better, great. If it's worse, go the other way from your starting, baseline number until happy.
5. When you get signal reports, or if you can monitor your output yourself, try further BFO settings that yield a higher/tinier voice rather than warm, lower voice tones. Higher vocals punch through noise better and with 5-12 watts output, you'll want every edge you can muster.
6. Frequency calibration: I prefer to do this regardless of CEC firmware version - Using a redundant rig, find WWV/WWVH on 5, 10, or 15mHz in the AM mode. Then, find the same station with your uBitx and leave the dial on 5.000 or 10.000 or etc. Just do it. Also, set the uBitx tuning steps to 10hz. Now most of the time, WWV runs a tone that's obvious as a heart attack interrupted with one-second "toc"s. I don't know the tone freq (1000hz? 1200hz?) but that's irrelevant. Put the uBitx in Calibrate mode and set the radio's apparent volumes to about equal... not loud, not whisper soft either. Whereas other directions call for a zero-beat, we are going to listen for a hetrodyne beat. Adjust the uBitx so that it receives the same noooooote/toc/noooooote/toc/noooooote at the same pitch as heard on the redundant radio. Yeah, you"ll pass by a textbook zero-beat in the process, though, aligning the musical tone is more accurate. If one radio's tone isn't "toc"ing , you're uBitx is lined up on the carrier and not the note. Find the note, yet, if they go into some weather report or something like that, you'll have to wait. When you get super-close to the two sources beating against each other, you'll hear a "wobbling" of the notes in between the two radios. The cycle rate of that "wobble" is quite literally the difference in Hertz or cycles between WWV's atomic clock and your uBitx dial! Talk about accuracy.... With only 10Hz resolution on the tuner, you can get within 5Hz, in theory. I'm typically 2 to 4 off, as it happens. When close, press the mike PTT and store this setting.
7. Cycle off the power to the uBitx.
8. Power it back on, and reset the dial to WWV. It should come up just as sharp and close as it did in the calibration stage. If not, did you store it first with a mike press before cycling off & on the power?
And - yes, I align and calibrate stuff for a living (just not radios, now) and also help write training and SOP's with a state agency; please bear with the dry, direct writing style!
Please try these methods and report back, OK?