.pdf files dont work correctly after npm run build

Hi guys i just finished my react project and i used i there this piece of code to show pdf on button click:

import Pdfbivykell from 
'../assets/katalogovelisty/fitness/14bicykel.pdf';

<a href = {Pdfbivykell} id="unclick"><button>Katalógový list</button> 
</a>

and the thing is that when i running a local host everything works fine, but after i build it with npm run build and upload it to my hosting the pdf opens at first time but when trying second time and it can be another pdf it wont open the pdf but some other subpage

for example here is my uploaded page : the button that open pdf is called "katalogový list"

https://oliihriska.sk/Hraciezostavy - here are products

https://oliihriska.sk/Hraciezostavyhrad - and here is the specific product with the pdf button at first time it will open right and then just open subpage but after eraseing the history of the browser its opens again at first time