Bug: Torrent seed reports continued downloading & ratio at 0 | Tribler 7.2.1, Win10x64

[Brassfield]

Please, fill all relevant items:

• [Y ] I have read CONTRIBUTING.rst

• [N ] I have tried with the latest pre-release version and I still can reproduce the issue.
  But it happened on both 7.2 and 7.2.1

Tribler version/branch+revision:

7.2.1

Operating system and version:

Windows 10 64bit

Steps to reproduce the behavior:

Copy file/folder into TribblerDownload tree (e.g. latest Kali images, etc.)
Add existing torrent of file into Tribbler
Begin seeding

adding additional testing in comment below - strange behavior continues after deleting a file and force rechecking the torrent

Expected behavior:

Torrent reports sending data, but not downloading data
Ratio null or positive
Token balance increasing?

Actual behavior:

e.g. kali light 2018-4-amd64
Details: Ratio 0, up: 808.5 kb, down: 332.4kb

Both download and upload continue to increase. I don't know why download is increasing, as the file was complete when initially added to Tribbler & the client hasn't reported any download speed.

As well, my token balance continues to increase.

Relevant log file output:

[Brassfield]

This is likely related to: #4161
But I didn't see any phantom download reported there.

[Brassfield]

This torrent has 2 files - the iso and a 100B sha hash.

I stopped the torrent, deleted the sha hash file, force rechecked the torrent. It's correctly recognized as 99% complete. I restart the torrent.

Acc'd to details:
the 100b file required >400kb data to download
ratio is now reported at >22x (reported up/down should be more like 2x; assuming up figure is accurate, the actual ratio should be 13000x (~1.3M : 100b)

[ichorid]

Token mining and torrent ratio-related stuff to be discussed and reported in #4363