Hi - is this with a Puck.js v1 or v2?
On the v1 the NFC coil ran a little too close to the aerial and that affected the performance in some directions. On the v2 the situation should be better, but I'm afraid it's still going to be directional as there's a big metal battery in there which will shield the radio transmission in some directions, and even ignoring that the aerial itself doesn't have a very even transmission pattern (image attached).
It's an unfortunate side-effect - the ceramic aerial gives you better signal strength vs a PCB one, but it's more peaky.
I'm afraid there's not really a fix, apart from to position the Puck such that the angles you are at relative to it are where the signal strength doesn't change too much.
Otherwise I do sell MDBT42Q modules with an antenna connector (https://shop.espruino.com/mdbt42q/mdbt42q-breakout-ufl) and with the right antenna on them they'd be a lot less changeable based on direction