Problem on startup with usb connected

Good morning everyone,

I have an iMac13,2 (Late 2012). Unfortunately, for some time now, starting it, it stops on the white screen and does not proceed with loading the operating system.

Two usb ports are connected to the Imac (1hd ssd and a separately powered hub). If I unplug the usb ports the mac starts up normally and plugging them back in there is no anomaly. The only anomaly to notice. If I unplug them, the Mc starts regularly. Now you understand that I can not keep plugging and unplugging at every boot. I checked all partitions with SOS from disk utility but no error emerged. The disk inside the mac is configured correctly as a startup disk and the other connected hard disks have no boot partitions. Please if anyone has a solution I would really appreciate it.

Thanks for the attention.

Sincerely