M Engine Memory in Azure Analysis Services

Hello,

I deployed tabular model to AAS. This model is getting data from Azure SQL Database using M code.

Lets say, the size of the model is 1GB.

Processing of the model takes another 2GB (but its only one short-time peak).

But here is the interesting part: 

After processing is done, the overall memory in AAS is showing 2GB, not 1GB.

This 1GB increase is due to "M Engine memory", which doesnt drop to 0 after processing, but keeps at 1GB and stays at this level.

When I reset the AAS (pause and start), this "M Engine memory" is cleaned.

But only till the next processing.

What to you think, is this behaviour normal?

Why the "M Engine memory" doesnt go back to 0 after processing?

Thanks in advance.