What have you done so far to correct the eyelashes on the back?
I have a Gammil. To correct this issue, the first 2 steps were, clean out all lint. Then oil and wait until tomorrow for the oil to travel through the machine. And the resevour of the oil must be kept moist during the quilting. The TEX of the thread must be > 28 or it breaks. Now that the machine is clean, oiled and using an appropriate thread (and needle is sharp), back to "Every time I change my bobbin, I do check my tension. I use a TOWA gauge to adjust my bobbin tension, then play with little loops on a muslin sandwich to check my tension on top and make any adjustments necessary to have perfect tension." Having said all this, your machine may not have the same quirks. So contact the company.