Been getting worse. Does this often now.
The bouncing is because the nozzle is too low and dragging across the infill.
I have been battling this same problem on my Taz Pro for 9 months now. What I have found is that doing a Nozzle Calibration (https://www.printyourmind3d.ca/blogs/tutorials/how-to-calibrate-the-lulzbot-taz-pro)
Then I do a test print and check the Nozzle Z-Offset by watching the first layer to see if it is ‘too squished’ or ‘not squished enough’. My Z-Offet is set to -1.35mm at the moment.
I find that I have to redo this calibration process every 100 or so print hours.
No, the bouncing in my case was perpetual, as soon as you turn on the machine. I guess in my case an actuator in head 1 had failed. It’s been replaced, and I’ll be testing it shortly.
Oh, that is the actuator failing to find its position. The actuators are custom made for a Canadian company called Actuonix. I have a bunch of the same but longer and they give out relatively quickly. I would contact Lulzbot and if the printer is in warranty get a replacement. Otherwise you are dealing directly with Actuonix.