Sims won't use gym equipments

I built a gym for Dina and she's doing awesome except that sims will only use the threadmill, i remove the threadmill, they dance, I remove the sound machine, they go to the balelt bars, I remove the ballet bars, they junt stand there doind nothing, even with 10 equipments avaliable. Does anyone knows why does this happen and if there's a mod to fix it?