Microprofiler clarification: "StreamingObserver sets change"

[handbookleaker]

I tried to check the microprofiler to see why a game server is lagging, and I just get a vague answer of this taking too long:

Any idea what this could be or what causes it, and how to maybe mitigate it?
Many thanks in advance.

[xnlogical]

Instance Streaming if I had to guess.