Yesterday i have start a martingale to rollin, but later more bets, i see "connection error" and the bet are stopped. This for me is the most risk of martingale choice (later stopped i have lost last 8 bet)
You could continue rolling manually. You just had to check your last few bets and make some calculations and do few manual rolls untill you win.
You can then start auto betting again. So no big deal.
if you have 1000btc and start very low it could work out but nobody play with these big amounts
Starting very low is not a good choice in martingale. If you start with say 10 sat as in very low it will take you ages to make huge profit and the time you would be spending will not be worth!