I found a solution (by downgrading the BIOS), but it was tricky since I couldn't do this within the BIOS menu by using a USB (since the USB wasn't being detected), and the laptop wasn't booting into Windows:

My 5320 had to be plugged in otherwise the laptop just wouldn't turn on.

I kept trying to turn on the laptop and after many attempts I was able to go into BIOS. 

Even when I had a USB plugged in containing the BIOS version 1.13.0, it wasn't being detected in the BIOS menu so I couldn't downgrade within the menu.

So when in the BIOS, I clicked on SupportAssist OS Recovery.

When that loaded, I clicked on the three dots in the top right corner and clicked restart.

I then pressed F12 again, went into the BIOS and now "Windows Boot Manager" was appearing on the left hand side in "UEFI Boot Devices" which wasn't appearing before.

I then clicked on that and the laptop booted into Windows.

Twice the laptop just blanked out and shut down at random times after this, but on the third time I was able to quickly download BIOS version 1.13.0 from Dell's website and then execute the program. I could have also just used the version on my USB, but any interruptions in the BIOS installation and the laptop could be permanently damaged, so using a USB is potentially risky. The laptop then installed BIOS 1.13.0 and restarted, but it still wasn't booting, so I had to do one more thing.

I followed the instructions on someone else's post who had this same 1.14.3 BIOS issue who said do this after downgrading BIOS:

1. open bottom cover

2. unplug charger and remove battery

3. push power button for 15 seconds

4 plug in battery and charger

5. push power 

After this, the laptop was fine again with BIOS version 1.13.0

 

Finding older BIOS versions isn't very clear on Dell's website, so go into drivers and updates, manually search, search in the BIOS category, click the dropdown arrow next to the download button, and the older BIOS versions are there.

 

I hope this helps, and Merry Christmas!