@Monika1983 

Never use a journal entry  for inventory asset if you are using invetnory items - it messes up the balance sheet vs inventory valuation.

Seeing a bill in COGS is normal if you sold to a negative on hand.  When you sell to a negative on hand, QB uses the present average cost to post to COGS for the sale and sets the qty on hand negative

then when you buy more, QB compares the present average cost to the cost used at the time of the sale, and if it is different it makes an adjustment, that adjustment is what you see as a bill in COGS.