Strange behaviour of my phone

Some strange behaviour with my smartphone a Sony st21i. I have a PC and an HP monitor with usb connections. I also have a usb 3.0 hub connected directly to the motherboard on the tower. Everything is fine, except,

When the usb cable is connected from the monitor to this hub, on startup, fresh in the morning, the computer will pause at the logo screen for maybe 5 minutes before continuing on to boot-up. Took me a while to figure out what the problem was, then I simply disconnected the monitor cable from the hub and the boot continues normally. Also, if the cable is connected in that way, shutdown will function in the same way.

The other oddity is,

When I connect my smartphone to the monitor, with no usb cable connected from the monitor to the hub or the PC, the phone battery will still charge. However there will be no connection to the computer as an additional drive to sort out files etc. Then, if I plug the usb cable to the hub, it will connect as a new recognised drive.

How can it charge if the usb cable from the monitor is not connected? And
Why this strange behaviour?

Not sure in the boot issues but I'm guessing the hub on the monitor is powered from the monitor aka active hub.

The usb monitor should be directly connected to the mobo on it's own port regardless of anything else. The hub should be reserved for flash drives, mouses, etc.
"with no usb cable connected from the monitor to the hub or the PC, the phone battery will still charge. However there will be no connection to the computer" - obviously
As for the charging issue. Does the monitor not have power or is it usb only? Sounds like a capacitor if usb only.

Yes, thank you for that: to connect the usb from the monitor directly to the mobo. Will try that today. I think it used to be like that, then a changeover (to the hub) with the last computer rebuild, thinking it didn't matter. Yes, the monitor has external power from the mains, if I understand the question correctly.