I forgot to mention that I already tried changing that argument.
We assume that you are using custom board and not PSoC Development kit. Did you take care of the VBUS pin? The USB PHY is powered by the VBUS power pad of the PSoC device. The VBUS pad can be driven either by the host VBUS (bus-powered) or by external supply (self-powered).
That did the trick, thanks!
I thought the VBUS was only used for detection, and since VBUS Monitoring was disabled in the configuration of the USBFS I thought it was redundant.