Trying to download a large file (80Gb) from shareable link, but only 39 Gb downloads every time.

Thanks Nancy that's really helpful.

Since posting on here, it seemed the sync had got stuck (the bar wasn't moving and the counter wasn't moving down at all), so I restarting my computer (as i read on here that sometimes helps) and when I opened Dropbox again (desktop version,)  instead of saying 2 days it said 4 hrs and was counting down, so that felt like a breakthrough.

However - my available storage had all of a sudden gone down from 200Gb to 40Gb. So although it was syncing, I was worried this would ultimately mean the sync/download wouldn’t complete as not adequate space. I tried clearing some other files on my laptop and managed to get my storage space up to 95Gb, but again, the syncing then seemed to stop (it still had the blue syncing icon but the counter wasn't going down.) so I then paused the sync, and restarted it to see if this would kickstart it again, and as feared, I got an error msg saying not enough space on my device.

This was so confusing as I originally had enough space (200Gb) before attempting to get this file, but it seemed the unsuccessful syncing attempts were taking up space on my laptop.

After doing some research I saw that 'Dropbox' on my laptop was taking up  171.65Gb  of space and that it could be down to caches, so i deleted these files, and thankfully got back up to 240Gb storage space again. 

So, I'm back to having adequate space on my laptop now, and have restarted syncing. And thankfully the counter seems to be going down and it's saying 3 hours (not 2+ days!) But my storage on my laptop automatically went from 240Gb to 98Gb the minute I started syncing. I assume this is because it's already using the storage for the file it's syncing, but it's saying it's got 130Gb left to sync on the counter (it's slowly counting down) so I am very concerned that because my laptop is saying i've only got 90Gb available, i will once again run into issues and be told I don't have enough space. 

Does anyone know what I can do in this instance? I am at a total loss as even if i have adequate space for the sync/download, I then seem to lose all this space the minute i start to sync, which then means the sync fails. Any help would be so welcome, thank you.