When the guardians and the elder guardian are out of the water and they jump and attack them floating in the air as they attack

Confirmed for 1.0.0

When spawned on land, the guardians jump in the air and float there whilst attacking. (In the Java version, they continue to jump as they attack)

Me too, but in Beta 1.2.20.1

For the issue where the guardians are jumping out of the water, please see ticket MCPE-32442