Did you give it enough time to start? My model does start after ~2.38sec.
I tested with KiCAD 7.0.8
Simulator, Sim Command, Transient tab, 1m in Time step and Final time set to 3 seconds.
Please see attached picture:
Zoomed in and more signals - the plot looks like this:
NE555.lib file downloaded from here: KiCAD forum
---EDIT--- To check if skipping is present.
This is my result when setup is: transient: 100us step, 3 to 4 second simulation. Voltage seems to be a bit unstable, otherwise fine (no skips).
Other setup: 10us step, other parameters the same.
And the last one: 1us step.
