You are having a delusion to think that provably fair is a system that is preventing you from getting 20+ loss streak and you should learn about provably fair first before even considering posting about such things (reference below )
Provably fair system is there to help the player to notice if by any chance the site owner decide to rig the rolls. It is helping you to verify your rolls and not to help you win on the site. Any site that use moneypot's API is fair and each rolls is verified automatically in moneypot so there is no chance for a site that is using moneypot to rig your rolls
References on provably fair : http://dicesites.com/provably-fair
I know about the provably fair system they have and many people trust on them but when i got compared with their plinko games with luckybit than they have totally different result because on that site i never got such a losing streak like that so i have doubt about their provably fair system with plinko games.
You know about provably fair system but you doubt it just because a loss streak? Does it mean that you will doubt all site's provably fair system where you get loss streak and only believe on site where you do not get loss streak?
As what arallmuus said, it is not a system to prevent loss streak. So I'd say you just got a bad luck on those 20+ losses streak...