I placed a trade on Interactive Brokers and it was partially filled, if I amend the order will I be charged the minimum commission fee again?

Hello Anon! Yes, you will be charged twice for the comission fee. This is probably due to the settings of the "Market" when you're buying. Though IBKR will help you purchase it at a reasonable price, it will however split your amount to various quantity. I don't like it as they charged multiple commission fee, adding it up to be a much more expensive lot than normal.

What I suggest would be to set the buy with limit instead of MarketPrice. This way, they will only provide you the exact quantity at the price you want.

Yes, you will have to fulfill the minimum commission fee depending on the product/market you are trading for both the first order (partially filled) and the second order (amended).