Bitcoin Trading and Leverage

Hello all, long time reader first time poster. Attached are two images from two demo accounts from different brokers for trading BTCUSD CFD’s. Both accounts are set to 100:1 Leverage. Why is it the margin on a 1.0 (lot?) trade for one broker sets the margin at a fixed $3000 (it’s $3000 when BTC is valued at $9000 and $12,000 I’ve checked). If I enter a 0.5 trade (which is the minimum) it’s always set at $1500, where as the other one floats at 1/10th of the value of bitcoin at the time of trade.

Does it have something to do with the fact one is BTCUSD and the other BTCUSDm?

Is there a name for these two different types of brokerage accounts or can someone explain to me exactly whats going on?

Second picture can only upload 1 in first post as i’m new.

Btc is much volatile; so using more than 1:5 leverage can be dangerous! By the way; storing few cents of BTC is much better option (with a long time view) than btc trading!

I don’t now if this is the case (and I don’t trade Bitcoin or any other rat poison neither do I know which brokers you’re trading with):

Some brokers have fixed minimum margin requirements (in monetary terms). They’re usually the type to stay away from but that’s the answer anyway.

Ok great thanks for your reply, I hadn’t come across this fixed margin type broker yet so wasn’t sure why they would do it. And yes without naming them I’m getting the sense they may be very dodgy indeed.
Cheers