I know mine works that way (KOEO, starts at 14.7, warms up and then goes to 20+) because I've had the sensor die on my several times. Each time, it stopped responding and would only output 14.7. One died and stuck at 20.1 (reading on the handheld, at least).
I think in the dashboard it will list the temperature of the sensor too - but it's been a long time since I went looking for that.
The reason I question it, is that readings SHOULD change as the engine is running. My rpm fluctuates +-150 over time, and updates a couple times a second. Same for other readings. If they're steady and remain unchanged, that would be strange.
The MAP kPa reading should vary slightly at idle, and how it varies would give an idea of what might be going on.
I'd check idle vac using any of the ports on the back of the TB - also verify that none are unplugged or unused. I've had rough running at idle after a minor backfire blew a cap off mine (I have PCV hooked up, but no brake booster, so I have at least one larger cap).
