Tamas, it seems that your baro is either defected, or somehow it is disturbed by wind or light. Check that the sponge is in place inside the controller's housing.
This how the GPS.Alt and BARO.Alt should look like
And this is how yours looks like
The GPS altitude change occurs AFTER the BARO register a sudden change in altitude on the other direction... ... This is obviously bogus.
Look at this 1s... it supposedly lost 10 meters in 1sec, it should drop like a stone, and suddenly no more drop...
What kind of controller is it ?