Headset woes

Hi all,
I recently purchased a new frameset that came with a semi integrated headset. The cups were already pressed into the frame and the bearings came in a little box along with it. Wanting to build the bike up I took the bearings out of the box and wanted to drop them into the pre-installed cups, only to find out that they don't fit.
Now I am correct in thinking that the bearings in a semi integrated headset should just drop in right? They shouldn't be pressed in or anything? I have owned multiple frames with both semi- and fully integrated headsets and the bearings were always a nice fit held in place by the conical races supplied with the headset, not by forcefully pressing them into the head tube.
What's making me doubt my own knowledge is the unlikeliness of the manufacturer supplying the wrong size bearings for their own headset but they really don't fit. The bearings read 41.8, would a 41mm bearing be likely to fit, assuming the angles match?

headset types claims debunked > http://chrisking.com/files/pdfs/Int20HeadsetsExplained.pdf

headset types identified > https://www.canecreek.com/resources/products/headsets/technical-specifications/headset-identification-and-specification-guide.pdf

you'll need an accurate measurement device (a digital vernier caliper > http://www.ebay.co.uk/itm/like/301144353498?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&chn=ps&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108&ff19=0) to take measurements around the cups to determine deformation

they really don't fit.

I've experienced (semi) integrated bearings be everything from a snug fit needing a firm push with the thumb to seat to a loose enough fit that the lower bearing wouldn't hold itself in place.

I'd say if they really don't fit then they are probably the wrong size.

Are both upper and lower affected?

Could there be paint/powdercoat on the cups that means they are undersized?

Could there be damage to the headtube and cups?

What's the frame etc? Google might reveal the headset specs.