cat /etc/apt/sources.list.d/microsoft-prod.sources
cat /etc/apt/sources.list.d/microsoft-prod.list.distUpgrade
apt-cache policy mdatp
Enabled: no

Fix

sudo rm /etc/apt/sources.list.d/microsoft-prod.sources
sudo rm /etc/apt/sources.list.d/microsoft-prod.list.distUpgrade

curl -sSL https://packages.microsoft.com/config/ubuntu/24.04/prod.list | sudo tee /etc/apt/sources.list.d/microsoft-prod.list

curl -sSL https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor | sudo tee /usr/share/keyrings/microsoft-prod.gpg > /dev/null
sudo chmod o+r /usr/share/keyrings/microsoft-prod.gpg

sudo apt update
apt-cache policy mdatp
sudo apt install --only-upgrade mdatp