Sage Stuck in manual factory reset loop

[orthogonal]

Hi all. I bought a used Kobo Sage a few weeks ago and have been running into issues. After the battery has died (I think due to sleepcover accidental wakes while not in use), the touchscreen is unresponsive and backlight is off. I would be able to power cycle, but this would just land me back at the stock home screen where the clock is frozen to the time at boot and the KOReader menu option on the bottom bar is gone. I was able to get out of this issue the first time by doing a manual factory reset. This issue happened again, and this time I am stuck in what feels like a loop of an attempted manual factory reset. I will describe what the loop looks like to me, after starting the process by holding the page-turn and power button:

1. Device is at rest. Showing a graphic of a person pressing the power button on the back of the Sage. Power LED off.
2. I press the power button.
3. Screen automatically switches to 3 dots counting down from 3 filled dots to 1 filled dot then stops. Power LED blinks until screen stops last filled dot, then goes out.
4. Step 3 repeats automatically 4 times.
5. Screen automatically switches to a black screen with an ereader graphic with a warning icon on its screen. There is a rectangle below the ereader graphic with a circular arrow icon. Power LED is blinking then goes out.
6. Screen automatically switches to a black screen with a crossed out power button and 3 dots counting down over and over many times. Power LED is on steady.
7. Device automatically goes back to step 1.

Nothing I do seems to change this process, whether I press buttons or don't press anything. I am unable to just turn off the Sage where it shows "Powered off". At rest, the device is always at step 1. I've left it on a charger overnight, plugged into a power bank, plugged into a power bank with trickle charge, and plugged into my Macbook over USB. Nothing seems to affect it and it doesn't appear to mount over USB at any step.

Any help and tips would be really appreciated!