Windows keeps turning on Periodic Scanning.

Hello, I'm on Windows 11 from less than 1 month. I freshly installed it on 27th November. It was all fine, but after a week/ten days it started to show me a notification message on Startup. Doesn't happen always on every startup, but let's say 8 times out of 10.
It's "Windows Security. Periodic Scanning of Microsoft Defender is Enabled" In the following message it also says that I'm using another Antivirus, and it's correct, because I use Bitdefender Total Security.
Considering this issue started after ten days, I suspect could be an update that screwed something. I'm on 22H2 (22621.963)
The most annoying part, is that this also slows the PC after the startup log screen. I have to wait 5-6 seconds even to launch the browser. Basically, I have to wait for the notification to shows up, then I can normally use my PC
I tried to disable Periodic Scanning, but it keeps turning on by itself. I also tried to completely disable Windows Defender in Group Policy, but same, it keeps turning on.

I'll attach the notification it to this message, but it's in italian.

And you pressed the ... next to X
and chose not to have the Notifications shown from Sicurezza di Windows?

OAT said:

And you pressed the ... next to X
and chose not to have the Notifications shown from Sicurezza di Windows?

Click to expand...

I can't. It's greyed out. Anyway, even if I can turn off notifications, it doesn't change the fact that this scan keeps turning on, and slows down the PC on startup.

OK what do you see when you run: (WinKey +R) ,

shell:startup (enter)

This very site has this

OAT said:

OK what do you see when you run: (WinKey +R) ,

shell:startup (enter)

This very site has this

Click to expand...

Nothing, it's empty.

Thanks, I already tried that, but it keeps turning on by itself. That's why I think it's a bug introduced by some Windows Update.

Well uninstall the update and see.

I uninstalled all updates, and the issue is still present. That's weird. Can it be and internal update of Defender?

When was the last time BitDefender was updated? It could also be BitDefender causing issues.

Also - this is not an issue. Everything I've read and everything I've used alongside Windows Defedner, including BitDefender, recommends that you leave periodic scanning enabled in Defender, so it may be BitDefender itself that keeps re-enabling it. I had it on when I used Malwarebytes with Windows Defender, too, and it is on now.

Hi,
Periodic scanning is off and I use mbam pro
Updates may activate if you don't go through additional measure to limit defenders existence

MBAM pro will hijack access to defenders tamper protection setting though, without using/ enabling mbam tamper protection setting.
Really annoying trait just have to uncheck register with windows security and then defenders tamper protect setting is available again.

johnlgalt said:

When was the last time BitDefender was updated? It could also be BitDefender causing issues.

Also - this is not an issue. Everything I've read and everything I've used alongside Windows Defedner, including BitDefender, recommends that you leave periodic scanning enabled in Defender, so it may be BitDefender itself that keeps re-enabling it. I had it on when I used Malwarebytes with Windows Defender, too, and it is on now.

Click to expand...

I got that, but it's like a hourly scan, more than a periodic scan.

ThrashZone said:

Hi,
Periodic scanning is off and I use mbam pro
Updates may activate if you don't go through additional measure to limit defenders existence

MBAM pro will hijack access to defenders tamper protection setting though, without using/ enabling mbam tamper protection setting.
Really annoying trait just have to uncheck register with windows security and then defenders tamper protect setting is available again.

Click to expand...

Sorry, what?

Hi,
lol I'm saying it is possible for a third party security suite to hijack defender settings as I described mbam pro which is malwarebytes doing the same thing just a different defender setting.

Did you ever find a solution for this? Here it is more than a year later and I have the same problem on at least two systems, one Desktop and one Laptop. Haven't really paid attention to my other desktops, or my wife's laptop. I really don't want Defender doing periodic scans on its own. I use Acronis Cyber Protect Home Office, so I don't need Defender scanning and slowing down my already slow systems, as Acronis already does this.

Just a suggestion, have you tried disabling Windows Defender tasks in Task Scheduler?