I've noticed that while the last mm or so of insertion has friction, the
'click' happens early. This means the jack can be pulled out about a mm
or so (causing music to pause) without the jack 'letting go'.
By comparison, my S5 headphone jack takes about the same amount of force to release, but it's more 'all or nothing'. It is either fully seated, or fully released. The Nokia 8 has a bit of an 'in between' area.
The issue is much worse using non-mic earphones, I've noticed. They really don't seat properly.
Just tried an in-store demo model - it was faintly better than mine, but still very, very poor compared to every other model of phone. Hard to believe Nokia could stuff up such a simple, easy part of the design.
I have also inserted my Nokia headphones in my laptop and fits tight so thus my surprise at the Nokia 8.