Since for some weird reason neither me nor orv can post in your thread.

Here is the answer:

Actually this is not exactly a bug!

If you sit out while you are big blind and then sit in, then you have to repost the big blind. Although on your table total you lost 2000$ this way (the big blind), your total money amount is correctly not affected.
This way if you bet all your money, you bet all the money you had on the table. The thing is that this way you bet all your money but those 2000$. So if you lose, you lost everything but those 2000$.

This way you don't refill, you just play from your own money! And since this thing can maximally be the amount of the big blind of the table is not affecting the small tables more than the big ones.