Pc fans randomly stop spinning

So i hav a total of 8 fans in my pc and they are the daisy chainable uphere u2c and they have worked for 2 weeks without issue and randomly 1 set of them stopped working however the first fan in that bank of fans is still spinning and the other 4 fans in that bank are not spinning so it cannt be software (i dont think) as there is 1 fan spinning and the other fans do have power as they have the rgb still on them working perfectly fine, this has worked in the past and nothing has been changed that could have caused them to stop working