I use an inexpensive 4-port powered USB 3.0 hub from Anker. Not very rugged, but it does the job. The only issue I've ever had relative to Stellarmate is that the Serial Port Assistant gets confused and won't consistently assign port names. Probably important to note that I use an iOptron CEM60, which itself has a built in non-powered USB 2.0 hub. In my configuration, the CEM60 connects to one port on the Anker hub, and the iOptron hub (imaging camera, guide camera, focuser) connects to another port on the Anker hub; this then plugs into the Stellarmate.

www.amazon.com/Anker-Ultra-Slim-Portable...tebook/dp/B0192LPK5M

I'm using an Anker 7-port powered USB 3.0 hub. The serial port assistant got confused on this hub, so I plug the mount (NEQ6-R Pro) directly into the Stellarmate. The hub is plugged into the Stellarmate, other devices into the hub.

www.amazon.com/gp/product/B014ZQ07NE/ref...04_s00?ie=UTF8&psc=1

This hub has worked out well for me in the cold. Not using Stellarmate, but am using a Raspberry Pi as the full system.
StarTech.com 4 Port USB 3.0 Hub - 3 Dedicated USB Charging Ports

Any of the startech Hubs work well, as do Anker ones.. also I have used an Orico one too...

This Orico 4 ports works very well.

www.orico.cc/us/product/detail/574.html

But I got another 7 ports Orico USB3.0 hub which having issue with Raspberry pi.

www.amazon.com/ORICO-H7988-U3-BK-Compact...dapter/dp/B00A525AJO

I have had similar issues with the same hub. If I want Ekos to see the mount or the GPS USB dongle, I have to plug them into the Pi, not the hub. I haven't tried a USB 2.0 connecting cable, I've no reason to believe that would solve the problem but I'm gonna give it a whack. Important distinction about this particular Anker hub is that it runs off 12V, so you can cut the cable off its wall-wart and wire it into your battery system.

Sabrent 60W 7 port USB3 hub works well.

I also use Sabrent 7 Port USB 3.0 hub.
No complaints.
www.amazon.com/dp/B00SIQIV04
I also power my RPI from one of it's charging ports.

I use the ORICO HF9US-2P-BK 9 Port USB Hub that has an extra 2 dedicated powered USB ports. One to power the pi. It all works flawlessly.

BTW the Belkin hub I use does NOT power the Pi from its dedicated charging port. No idea why.

I'll second this one here.... www.amazon.com/Anker-Ultra-Slim-Portable...tebook/dp/B0192LPK5M

I use an ioptron ieq45 pro, Moonlite focuser, StellarMate and two ASI cameras.

Anyone using an
APANAGE 8 Port Powered USB 3.0 Hub Splitter, 4 Port USB Data Hub + 4 Smart 2.4A Charging Ports USB Hub, 12V/4A Power Adapter ? Price looks good ($Cdn)

www.amazon.ca/APANAGE-Powered-Splitter-C...dapter/dp/B07H19K7H3

[EDIT: I now have this, and find it works well powering the RPi3B+ and at the same time my Nikon Z7 using a Case Relay. ]