Avira antivirus somehow blocks game updates and installs

[Superkumi]

I'm running Windows 10 64bit, two weeks ago I installed Avira Antivirus Free, and after a few days noticed that games don't update and install.
Everything else in Steam works fine.
I tried uninstalling Avira, but this didn't fix it, which leads me to believe Avira changed something in my settings somewhere, maybe in the firewall.
I tried reinstalling Avira and checked everything I could think of to allow Steam through the firewall and Avira itself, but this doesn't seem to work.
Any help in identifying exactly what changed and where would be greatly appreciated.

[Cathulhu]

I'd contact Avira support and notify them about the issue.

[[wan-clan.org] Gordy Freeman]

The free trial of this fixed that issue last time I had it:
https://www.vipreantivirus.com/home-antivirus/internet-security/trial.aspx

You can safely uninstall it after it had done its stuff.

[Superkumi]

What "stuff" is it supposed to do?
I've installed it, problem persists.

[Superkumi]

By the way, selecting other download regions, disconnecting to my internet and connecting to the neighbour's, all don't help, no change at all.
The problem is strictly in the games downloading/updating section, it just doesn't start and stop.

[[wan-clan.org] Gordy Freeman]

Try TCP mode.

[Superkumi]

Tried it, no change (not that I'd know if Steam is actually in TCP mode, but it should be).

[[wan-clan.org] Gordy Freeman]

/facepalm.

Try it please.
https://support.steampowered.com/kb_article.php?ref=5623-QOSV-5250

[Superkumi]

That is precisely what I did, but it doesn't write "TCP mode" anywhere so it's not like I can know if it worked.
I mean, everything seems regular.
BTW, in the downloads section it shows the green disk line flat, blue network line isn't there, though might be hiding behind the green line and also flat.

[[wan-clan.org] Gordy Freeman]

Try disabling Windows Firewall, your NAT/PAT Router should protect you anyway.

At least for 30-60 seconds, then you can isolate the problem more.

[Superkumi]

One of the first things I tried was disabling firewall and antivirus.
The only thing I can think of is that Avira changed something else and didn't change it back when I uninstalled it.
This is by far the worst thing that ever happened on Steam to anyone ever in all time.

[Superkumi]

Anybody else got input on possible ways to fix this?
Maybe Valve is willing to respond to my support ticket?

[[wan-clan.org] Gordy Freeman]

Valve Software do not check the forums.

[Superkumi]

I know, that was just my way of expressing the incredibly unsatisfying unresponsiveness of Valve to support tickets.
Anyway, I'm almost desperate enough to reinstall Windows 10 and hope it will reset all security related settings that might have been affected.
Opinions?

[Superkumi]

Can anyone give me an alternative before I revert to a restore point in hopes it will revert Steam to working downloading condition and, if that fails, just flat out reinstall Windows 10?