FW 11.0.1 / AMS 18.0 : Random black screens & Switch won't connect to PC

SPECS:
Non-patched Switch / OFW 11.0.1 / CFW AMS M 18.0 previously - M 18.1 currently.
Running latest versions of all other apps discussed below.

Both problems started earlier today after trying to connect my primary Switch to my secondary Windows 10 PC.

Random Black Screens:
It can happen just before reaching the Switch logo after injecting payload or upon accessing the Homebrew Menu from either the applet or holding R and starting an installed application. The screen goes black, the back light remains on, no error message is displayed, and the system becomes completely unresponsive but doesn't shut down. I have to hold the power button to force shutoff. It seems to happen more frequently when plugged into either of my PCs via USB but I haven't yet tested that thoroughly enough to be certain of a correlation.

Connectivity Issues:
My Switch won't communicate with my main Windows 7 PC. I have the Libusbk driver installed via Zadig, Windows Device Manager recognizes it as a Libusbk device "Nintendo Switch", and it both charges and I can still inject payloads, but no homebrew apps I have such as Lithium and DBI - a file manager - recognize a USB connection. I've tried two separate Switch Pro Controller USB-C cables, both of which worked fine yesterday, and have tried the process on two separate Windows PCs to no avail.

I first noticed this problem earlier today when trying to connect my Switch to my Windows 10 PC for the first time. I first connected my Switch which was recognized in Zadig's drop down menu, installed the driver, the PC recognized the Switch as a Libusbk device but my system wouldn't communicate with my second PC. This was also the first instance of a random black screen happening while trying to access the Homebrew Menu while still connected via USB. Upon reconnecting my system to my primary Windows 7 PC I found it was no longer recognized as a Libusbk device. It had reverted back to the default driver and I had to reinstall it. Unfortunately it still cannot communicate with either system. What's more I can't get Tegra RCM Smash to recognize my Switch on my Windows 10 PC but it does on my Windows 7 machine.

Everything else works fine. The system otherwise operates normally and installed games run, though I've yet to thoroughly test it. I even dumped a game to my Windows 7 HDD via USB last night with no trouble. As such it shouldn't be a problem with my SD card or CFW, but short of some bizarre hardware fault I can't think of anything else.

Any help would be greatly appreciated.

UPDATE:
I've tried connecting my second Switch - an unpatched unit running OFW: 10.0 / CFW: AMS M 18.0 - to my Windows 7 PC and it is both properly recognized and communicates normally. This would seem to prove that the problem is somehow related to my primary Switch and my PC or driver.

UPDATE 02:
My secondary Switch - which communicates properly - doesn't seem to register in Windows Device Manager but is showing in Zadig registered as "Nintendo Switch" using driver HidUsb (v6.1.7601.18199). When running DBI's MTP responder it's registered as "DBI" using driver WUDFRd (v6.1.7601.18738). When running Lithium it's registered as "libnx USB comms" using driver libusbK (v3.0.7.0). When running NxMTP it's registered as "Switch" using driver WUDFRd (v6.1.7601.18738). It also doesn't black screen when accessing the Homebrew Menu.

My primary Switch registered in Device Manager as "libusbk device - Nintendo Switch" after driver installation but doesn't communicate. Uninstalling that driver with the Switch connected reverts it back to HidUsb (v6.1.7601.18199) but it still doesn't communicate and continues to randomly black screen on the Homebrew Menu. Utilizing the same homebrew mentioned above in the same way does nothing. They don't register in Zadig.

Both systems, when powered off, register in Zadig as "APX" using driver libusbK (v3.0.7.0).

My secondary Switch continues to operate normally even with the libusbk driver uninstalled.

UPDATE 03:
I've reformatted the SD card used in my primary Switch. No corruption was detected. Fresh installed AMS M 18.1. System still will not communicate with my PC.

UPDATE 04:
I failed to mention earlier but when launching Lithium it gives the error messages "Failed to enable DS" and "Failed to initialize usbDs! 62977" A cursory search online has shown others with the same problem albeit a different code. The apparent solution was to update their homebrew but I'm already running OFW 11.0.1 / CFW AMS M 18.1 and my Lithium, DBI, and NxMTP are at the latest versions which all worked previously before the inciting incident on the morning of 02-24-2021.

 

Thank you both for the response.

Firstly, I stated in the OP that I have two Switch's, a primary and secondary unit, both unpatched, both running AMS M 18.1. The primary unit is on OFW 11.0.1, the secondary is on OFW 10.0. My secondary Switch communicates with my Windows 7 PC just fine, as my primary Switch used to, so it doesn't seem to be a problem with cables, my PC, or drivers. My Primary Switch was also communicating normally less than a day ago. I've done nothing to either of my PCs in that short interval, no updates or installations of any kind. I dumped a game from my primary Switch via USB to my Windows 7 PC without incident. These problems only started after connecting my primary Switch to my Windows 10 PC and attempting to install the libusbk driver. I'm uncertain if that was the inciting incident or if it was unrelated. As such I'm leery of connecting my secondary Switch to my Windows 10 PC until I've ruled out other possibilities.

Secondly, concerning hardware failure, I certainly can't rule that out but I'm not familiar enough with the Switch hardware to know what could causing both the communication problems and the random black screens, or causing them separately. So far the black screens only happen after the Atmosphere logo on startup, when trying to access the Homebrew Menu, when running homebrew from the menu, or via NSP forwarder. They also happen regardless of whether my primary Switch is plugged into either of my PCs. I haven't yet triggered a black screen when executing or running a game, and I've been playing games installed on the SD card as well as internal memory. I've reformatted my SD card twice and checked for errors, it doesn't seem to be a corruption issue but I'll be buying a new SD card to test just to be sure.

What's stranger still is that others have had these same issues but they were tied to compatibility problems between OFW, CFW, and hombrew. I'm using the latest of everything I have which was working perfectly not more than a day past.