Four or five years ago, there was a thread discussing the quality differences between cheapo live centers and spendy ones. The conclusion was that the spendy ones were much better.
I commented that given that my Grizzly live center cost something like twelve bucks, I could replace it many times for the price of the 'good' ones and that I likely wouldn't need to replace it that many times.
Based on that thread, however, I got nervous that my cheapo live center was going to die at the perfectly wrong time and leave me in the lurch. This resulted in my buying a spare one just in case. That spare is still in a drawer in our shop. Of course, the price on that cheapo live center has dramatically increased all the way to $14.95.
My point is, if you are having trouble with your live center, throw it in the trash can and buy a replacement. A cheapo replacement will be far better than the one you having trouble with.