Why does the adjustment/gain/loss show a negative amount on my 1099B review? I did not lose money selling stock

You would typically show a loss form entering a form 1099-B if the cost basis was more than the proceeds. I suggest you go back through the entry and make sure you entered the proceeds and cost basis correctly.

brokers are putting negative numbers where they are not allowed, then claiming the IRS made them do it.

only the gain column can be negative (that would be a loss).

wash sale adjustment is always positive. and so is the money involved.  cost and proceeds.