Seemingly random server unresponsiveness

[KrissiHub]

When clicking randomly trough Plugins, sometimes for a small second an error appears and disappears again.
The error seems to say, that the server is unresponsive in this small time slot.
It does not seem to mess with the functionality, but looks kinda weird when the error appears in the upper right corner and disappears again.
Also I don't really know what could cause this.
Here is the console output for said error:

To recreate, just click random through some plugins