Order minimum - Brokerages

Hello, Although I’m sure this may seem obvious, I went to place an order today via CommSec however I was denied as my first order must be 100$ and every subsequent order thereafter must be 100$ and maintain a holdings of 500$.
Is this the case with all brokerages? And if not is it advisable to switch to another brokerage?
I’m sorry for the relatively basic questions, I have been researching lots of financial topics but little things like this never seem to pop up

Hello, if i can elaborate,
its called the minimum marketable parcel of shares
Would i be better off switching to IG Share trading?