High jitter also occurs when the signal is marginal and the client scans the WiFi frequencies for other base stations to associate to (on the assumption that maybe you moved and there is another base station with a stronger signal). Since it has to “tune” into the other channels to listen for beacons, there will be a noticeable jitter while it is not tuned to the “current” channel.

This is my understanding as I’m still learning. Fascinating this stuff works at all.

Not bad signal, but the basis of how wifi shares the spectrum is time distribution.