Yes, two 5V outputs. I agree the 15 seems odd now that you mention it. I will be digging into it again this afternoon. I’ll pull the power supply, I’ve read there is a tag under it that shows the outputs. News at 11.
If it is supposed to be 12 it could be too high for the component it is feeding, if it is supposed to be 24 then the low voltage could cause an overdraw of amperage, another bad thing. A lot of people don't realize low voltage can often be more damaging than high. It is common for a monitor to run on 12 volts.