Noise/feedback when listening back

There can be a second layer of “audio enhancements”,
sometimes called MaxxAudio

BTW Your Test2 does not have any mains-hum,
(but it has been processed: noise-reduction & noise-gate).

The brand/length*/positioning of the microphone cable can permit or block mains-hum.
Whatever cabling arrangement you had with Test1,
(which has the hum), should be avoided in future.

[ * use the shortest cable ].