No. I have never experienced this and I have never heard of this.
What kind of USB device is it? Is it possible that it's trying to draw too much power from the USB port?
Hiya both.
Yes, I've seen this.
However in my experience it is not particular to the Z390M Gaming or similar.
Because I take an interest in the USB sub-system, this had me worried a few builds back. I couldn't figure out what was happening. Until it clicked ... These are my conclusions YMMV.
Same symptoms - plug in a USB device and the screens black-out. Only temporarily though. They do cycle back.
Tried different devices - powered and unpowered. I have a selection of both. External 3.5" caddies with power bricks and standard 2.5" HDDS from Maxtor, Toshiba and WD etc.
The culprit was a 3.5" powered caddy with a "Type-B USB3" port - one of those square USB3 sockets with the extra bit added on top. Using the USB3 cable that was supplied with it, would not transfer data properly and caused a black-out. Using a USB2 spec transfer cable did move data, but still the video got temporarily killed when it was plugged-in.
By a process of trial-and-error I concluded this is an power-to-earth leakage problem. No harm
seems to be done to anything, but something trips. For me no other type USB connection causes this effect. The long, thin "micro-B superspeed/USB3" ports are fine, as are the standard "Type-A USB3".
I don't actually think the Type-B USB3 socket is bad in itself, but that the manufacturer of the caddy got something wrong and there is a leakage of power through to earth.
The only way to completely stop the black-outs was to use a USB Type B cable through an
extra USB2 extension to the motherboard. This somehow stopped the tripping, maybe by dropping the amperage leaking into the cable.
Hope that shines a light. Let me know if the scenario is different for you.