When using the start_paused switch to start the queue as paused, it causes the API call to fetch the queue to return a paused value of 1, an integer, instead of an expected boolean. In every other situation (including if you toggle the paused/resume state), it returns a boolean of true or false.
Can you the show the relevant API output? So with start_paused off and on?
@sanderjo I also start my Sabnzbd paused, so I was able to reproduce this. Will fix!
I assume since you can replicate the issue you do not need the output, but I will still supply a screenshot to ensure there is no confusion. I was debugging with a user of mine, "Yours" was his output (where start_paused was enabled) and "Mine" was my personal instance where I do not use this switch.
This was received by calling <host>/api?mode=queue&output=json&apikey=<key>.

Thanks for the additional info, and thanks for analyzing this.
Will be fixed in 3.0.0!