Stuck in 'download mode' when trying to do a reset

I just got a S4 Active that a former coworker turned in. He claim to have done a ‘factory-reset’ but I am not quite sure to what extent that reset worked since the graphic lock is still active which he apparently never used. And I need to get past that lock.

From what I have gathered a real ‘factory reset’ should take care of this.

So first of all, is that correct?

Now, I can’t do the factory reset itself since I get stuck into download mode. I have followed all solutions I could find and the problem still stands.

The steps that I take are:

1. Turn off phone/pull battery for 30 min

2. Hold volume down + power to enter ‘safe-mode’ or whatever. And I am quite certain the volume down button is not stuck.

3. Get sent straight into download mode after that.

The volume button can’t reasonably be stuck. It makes a clicking noise and I can feel it physically click. It wasn’t stuck pre-’reset’ and when I enter download mode I can click volume down to cancel download.

What do I do here? Are there any other relatively easy steps to get pass the graphics lock?