Pedals able to turn when wheel fixed

I have a new Unicycle bought for me an xmas present. Dont think its a recognised make - imported from Germany.

After advise in another thread i have the pedals and crank tightened correctly. However, now when i mount i can feel the pedals move although the wheel remains stationary.

Is this usual, i get the feeling it is getting worse and may be happening when i am cycling (or trying to cycle).

Is there anyway i can correct this. It doesn’t look as if there is anything i can tighten.

Thanks in advance for your help.

how far do they move? It sounds like you have the same problem i did. Is there a key way in the hub that the hub slides into? pics? i think we need more info. Is it splined?

I had this same problem with a sun I bought through UDC. I sent it back and they refunded my money, less shipping. If the resistance is fairly consistent but you can turn the pedals without turning the rim, my guess it is a hub that is press-fit onto the axle and it was not pressed on tightly enough. My advice from there is simply to return it, if possible.