Transmission shows larger session transfer than I actually downloaded

I have downloaded only 1.51GB in this session, but Transmission shows Down: 6.02GB. Sometimes while downloading some file, I notice that downloaded file size decreases for no reason. Today I noticed that I had downloaded 1.44GB, grabbed a smoke, came back, and it showed 1.36GB.
Same with Total Transfer. When I add up all of my downloads, it's like a fourth of what transmission shows me.

Also, I notice a decrease in speed. Had no problem with 20.04. I'm running Ubuntu MATE 22.04.1 LTS x86_64.
Has anyone had this problem before? I'll be grateful if you share the solution.

P.S. I can try other torrent clients, but I really like Transmission.

I haven't encountered this (yet)
I do have some glitches on GUI level with transmission-gtk (not with transmission-qt) on UM22.04.1 but not on filetransfer level.

It could be a good idea to try another torrentclient for a while because of this:
You want to rule out that the error is transmission bound
so if another torrentclient has the same problem , you know it is not a faulty install of transmission.

One possibility is that your networkconnection is flakey.
Another one is possible failing hardware.

Normally TCP is used for filetransfer (also for torrents) which has error correction.
So errors (and therefore resend equests) are handled in the network layer, that means: before it reaches your torrentclient.

But: a lot of torrents also use UDP which doesn't do any error correction which leaves it up to the application.

The application (your torrentclient)

  1. receives a bunch of data , dutifully logging the amount it received
  2. checks for errors after receiving a number of blocks of data
  3. detects errors, so it needs to discard these blocks of data and ask for resending the blocks
  4. crippled data is no data so it has to lower the amount of received data.

I suspect a network issue also because you noticed a decrease in speed.

It may be wise to reset your browser to clear the address (and port) translation table (NAT/NAPT) beforehand.

Also, check the logs of your router for (dos)attacks or other anomalies.