Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
This usually happens when something is blocking the printhead from moving..
So heres what we need to do.. Open the printer like you are going to change the ink tanks..
Then, with the printer open, watch the printhead. Unplug the machine from power and plug it back in..
When the printhead tries to move, is it getting st uck on a cable, or a piece of plastic, etc?
Ahhh.. When you say it pops a wheelie.. It sounds like the right side is coming off the track / rails?
Once it stops moving, can you unplug it and then use your hand and see if you can feel under the right side to see if its on track.
And if possible, try to push or snap it back into place.. If we can get it back on the rails, that alone may solve this issue.
But if it is coming off the rails, that is absolutely the issue and this is what we need to address.
Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.
If definitely should not have one side raised and the other not...
The printhead wouldnt operate normally and be unlevel.. Also, that squealing sound you are hearing says there is a gear or motor thats trying to turn and move and is being stuck or blocked. You will need to fill around and try to see whats blocking the printhead from leveling out.