A T-Mobile software update installed overnight and this morning my Galaxy Watch 4 Classic, which always makes it through the night into the next morning, is completely depleted, stuck in a boot loop, and unable to even draw a charge.
I've already performed a soft reset and reboot the device multiple times to no avail, it's been on my charger for the last hour but isn't able to build or hold a charge and keeps boot cycling.
Everything was working perfectly fine until the software update overnight, don't think it's a coincidence.