newsequentialid() creating non-sequential IDs when inserts are 8s apart

Question

I'm using SQL Server 15.0.4236.7 and have noticed that GUIDs are consecutive if the row inserts are <8s apart.

Here are some examples:

Inserts were 8s apart:

Inserts were <8s apart:

Why is this?

sql server 2008 newsequentialid() problem does not answer my question.

The answers there fail to mention why the GUIDs are consecutive in some cases, and non-consecutive in other cases. They only talk about how the GUIDs generated are sequential in that the value increases.

I would like to know why the GUIDs are consecutive when the inserts are within 8s of each other.