Headphone sounds distorted after screen repair

Hey guys,

I replaced a screen on a iPhone SE and afterwards the headphone jack would output distorted audio (sounding like it was from the end of a tunnel, or the voices being muffled) but the speaker still works flawlessly. The only way the audio could be heard properly was if pressure was applied over the headphone jack. After finding out about this, I opened up the phone yet again and tried to put tape over the headphone jack to apply pressure when the front was put back on, this did not help, so I removed the tape and now even pressure does not solve the issue.

This was for a friend so is urgent.

Any help?