Bangle.js 2 cannot connect via BLE anymore

I decided to update the firmware from v2.10 to v2.13 this evening. When I connected my phone to the watch via nRF Toolbox as usual, I started the update. There was a failure. Every time I hit retry my phone reads '(number e.g. 3072) bytes were sent while 0 bytes were reported as recieved'.
The watch eventually refreshes and reads BANK0 invalid.
I can't reload the watch back to normal, so I keep retrying. The progress bar gradually fills up by a few millimetres every time I hit retry, so I keep going until the update is finished.
I can no longer connect to anything via bluetooth. I have tried a factory reset, I've tried rolling back the firmware (no such luck). I can access the launcher and clock face, but as soon as I try and connect to the web IDE or the app loader from any computer in the house I get a prompt saying "disconnected".

I look at the settings console in the web IDE and see

BT> SEND ERROR: NotSupportedError: GATT operation failed for unknown reason.
BT> Disconnected (gattserverdisconnected)
Disconnect callback... {"port":"Bangle.js 75cd", "portName":"Bangle.js 75cd"}
WARNING: [notify_warn] Disconnected from Bangle.js 75cd

These past few weeks I've been working on a programming project for college using both Bangle.js models, the deadline is incoming and I've really hit a wall. The program is working perfectly but I need a working watch to download and present it.

Is there anything I can do? Any help would be most greatly appreciated.

This may sound strange, but connecting my phone's WebBLE app to the watch did the trick! I downloaded updates from the app loader and I can now connect to any device normally.
Edit: Never mind, it won't connect anymore.

Hi - I guess you have an iPhone? Unfortunately this seems to be a problem with recent iOS releases and the NRF Toolbox app.

For Bangle.js 2 we're trying to get everyone to just use the App Loader to do the firmware update (https://www.espruino.com/Bangle.js2#firm­ware-updates) as it's much more reliable, but now you've started with the NRF Toolbox unfortunately you have to complete it.

• I'm pretty sure you can just keep clicking though on NRF Toolbox until it completes (even though it's painful I know).
  
• Otherwise, you might be able to use the Web IDE from your Mac/PC to do the firmware update (Settings -> Flasher) in the top right
  
• Failing that, do you have or know anyone with an Android Phone/Tablet? NRF Toolbox on that will 'just work'