Hi,
Static Master plan uses the current data to generate a net requirement, so if there is any update in the Master data it will not be reflected in the static master plan unless you recalculate/ rerun it.
Please refer to below mention link:
docs.microsoft.com/.../master-planning-setup
Example:
A new product is created, and net requirement process is run. Refer to below results:
It shows empty

Static Master Plan on Hand:
It shows empty.

Now Inventory is adjusted to 66,128 as show on the post:

Static Master Showing the same on Hand:
Finally Updated Static Master Planning (Rerun):
Quantity has been adjusted to the on-hand inventory.

Please mark the the answer as verified, if it resolves your query.
Thanks,
Inferifi LLC