What? I never needed to install a driver.

Well, for the purposes of communicating with a device in vendor-specific class, you did
If you didn't install the filter driver, then you must have erased TI's driver, otherwise you'd need the filter driver.

Is this the same driver gCn uses?

AFAIK, the gCn client doesn't require libticables to be installed, so I'd say no. Plus one of the gCn bridges doesn't need a driver because it uses HID class (like the HP Prime). The limited speed of HID isn't a problem for a gCn bridge, but it is a significant problem for handling large amounts of data on a Prime.

That's strange. I know I had issues when using a serial cable where TI-Connect would randomly stop detecting my calc for no reason, even after a reboot, then the next day, work again, but I never had it happen with direct USB nor silverlink (except that one time mentionned earlier, which was solved by disconnecting then reconnecting the calc).

TI Connect did the "Error device does not recognize the command" again this morning and I FIXED IT FOR GOOD! I installed the newer version from education.ti.com and it works now. I guess the older version didn't like me?