Pipeline stuck at "Acquiring an agent from the cloud" resulting in 45-min timeout and "Abandoned due to infrastructure failure"

My Azure DevOps pipeline fails during the agent provisioning stage. Every build remains stuck on "Acquiring an agent from the cloud" until it reaches the 45-minute timeout threshold and gets abandoned.

Exact Error Messages:

##[error]Remote machine provider issue: The agent did not connect within the alloted time of 45 minute(s). Pool provider seems slow, we notified pool provider at [timestamp], still agent has not started processing it. Pool provider delay(in mins): 45.0412

Followed by:

##[error]The request: 2886 was abandoned due to an infrastructure failure. Notification of assignment to an agent was never received.

Environment & Setup:

1. Agent Pool: Azure Pipelines (Microsoft-hosted)
2. OS Images Tested: ubuntu-latest, ubuntu-22.04, windows-latest (all experience the exact same failure)
3. Concurrency: Free tier (1 Microsoft-hosted parallel job granted and verified 0/1 in use before queuing)
4. Tasks: Docker@2 (buildAndPush to ACR) and AzureCLI@2 (update Azure Container App)