Yesterday I used the boinc "suspend network activity" for some test I was doing and then forgot to turn it back on.

Today, 24 hours later, I noticed there were 3 tasks "stuck" downloading. I could not get them to download. Tried suspending resuming both the tasks and the project

Did a project reset and got message "lost tasks resent" and the same 3 tasks were back in "transfer" and stuck.

Did a detach and re-attach, same problem: lost tasks were downloaded and stuck in "transfer"

Finally checked network and realized I had suspended network activity.

Well, even though it was suspended, it still send me some tasks albeit "lost"
They started crunching as soon as network was enabled.

I think that is normal behaviour. I have seen it many times over the years. If network activity suspended, projects will still update, it seems to be only the file transfer that is suspended rather than all network activity.

Oh that's right, I remember now.
I do this all the time to make my computer aware that I've changed something(s) on my Account page.
e.g. percentage of cpus to use.

Set for NNW.
Set Network Off.
Click Update.

I think that is normal behaviour. I have seen it many times over the years. If network activity suspended, projects will still update, it seems to be only the file transfer that is suspended rather than all network activity.

FWIW: I would consider the project sending a "lost" file to the host to be a file transfer.

FWIW: I would consider the project sending a "lost" file to the host to be a file transfer.

What is 'resent' for a lost task after an update is the job specification - what application is to be used, what command line or processing parameters, etc. If a data file needs to be downloaded, that's a separate operation which follows later, and may on may not be delayed by network suspension.

FWIW, I have a vague recollection from the early days of BOINC that manually updating a project during network suspension temporarily re-enabled networking - for five minutes, IIRC. But I haven't tested that or read about it happening for many years. The code may have been taken out.

What is 'resent' for a lost task after an update is the job specification

That makes sense especially in light of what happened when I switched platform to anonymous on SETI. I lost all the cuda60 work units. They were actually deleted from the hard drive. Later, I tried to restore them and was told to use the "ghost" protocol because SETI no longer re-sends lost tasks. However, Einstein does "send" lost tasks, but just the "job spec" and nothing is actually downloaded.

What if you don't want the lost tasks to be downloaded as there was a legitimate reason in banishing them? I don't see a way to stop the download and even a detach had no effect.

What if you don't want the lost tasks to be downloaded as there was a legitimate reason in banishing them? I don't see a way to stop the download and even a detach had no effect.

Just abort the tasks and report them. Then the tasks are no longer 'lost' but accounted for.