Missing Initial Launch Mode Burst Capacity in Lightsail Instances

I have launched a new Lightsail instance, which, according to AWS documentation, should receive additional CPU burst capacity during launch, referred to as "launch mode". This feature is expected to allow new instances to burst beyond their baseline capacity immediately after launch, thereby facilitating CPU-intensive operations such as initialization scripts. However, I observe that the instance starts with a CPU limitation of 20% per core right from the beginning, which is significantly affecting the performance of CPU-intensive operations that run immediately after the instance starts.

Details:

1. Instance Type: 4 GB RAM, 2 vCPUs, 80 GB SSD

2. Observation:

   • I have been monitoring the CPU utilization and burst capacity through CloudWatch metrics in the Lightsail console.
   • From the very start, after launching the instance, I observe a CPU limitation of 20% per core. There is no apparent initial burst capacity as described in the AWS documentation for Lightsail.
   • This limitation is affecting the performance of CPU-intensive operations that are designed to run immediately after the instance is launched.

3. Expected Behavior:

   • According to AWS Lightsail documentation, new instances are expected to receive an additional launch CPU burst capacity, which allows instances to burst immediately after launch before they have accrued additional burst capacity.
   • I expect to see a higher CPU utilization allowed immediately after the instance launch, as described in the "launch mode" feature of Lightsail instances.

4. Actual Behavior:

   • Despite the documentation, I observe that the instance starts with a burst balance of 0% and a CPU limitation of 20% per core from the very beginning.
   • CPU-intensive operations running right after the start of the instance are severely throttled due to this limitation.

5. Impact:

   • This behavior is affecting the initial setup and performance of my Lightsail instances, as I rely on the promised "launch mode" burst capacity to run initialization scripts and processes that are CPU-intensive.

Questions:

1. Is this observed behavior expected for Lightsail instances?
2. If not, what could be causing this discrepancy between the documented behavior and the actual observed behavior?
3. Are there specific configurations or best practices to ensure that new Lightsail instances can utilize the promised "launch mode" burst capacity?
4. Has there been a change in how the “launch mode” burst capacity feature is implemented for Lightsail instances?