Do you think it would be okay if I asked why my hours are being cut?

I just started a job a month ago. It’s a commercial cleaning company. What i do is I go to the bank one night a week and go to another bank the other night. O feel like I’ve been doing a good job and I haven’t had any complaints. I have 2 supervisors who trained me and then there is their supervisor who I’m in contact with regularly. I asked one of my supervisors and he said if I wasn’t doing a good job there either he or my other supervisor would tell me. Anyways, we use quickbooks and I was looking at my schedule. Usually its 2 and a half hours a shift but it looks like next week its being cut down to only 2 hours. Should I ask them why my hours are being cut?