What is the difference between Pixhawk 4 and Pixhawk 6C?

[Janno (Jan Ole Noack)]

Your APM has a full enclosure that already blocks direct airflow over the baro, so in your case no foam isn’t the end of the world.

@RudrakshTek

But still, is there any hope for my apm 2.8 barometer?

Did you do the tests Juergen suggested here:

APM 2.8.0 showing negative altitude when armed

I agree with all others that it would be the best to change to a actual flight controller. But still I am think about your problem. The local air pressure is never really static. It changes on local weather conditions, changes of hight over reference level and also on direct air speed at the sensor. So the algorithm of the flight controller (FC) must reset the ground level to zero just before take off. So if you power on the FC while the the drone is placed maybe on a work bench on a differe…

If yes, what are the results?
If no, do it!