Mainly you need to go very slowly in X.
Also, you need to test different types of accounts and proxies. 4G usually works well, but they tend to be more expensive.
The better the accounts, the quicker you can get started, but good ones need a warm-up too but you can also use cheap disposable accounts (although they also need warm up).
You also have to keep in mind that there is no exact equation for everything to work well in X, there are many variables at play and each case is a world, one can use bot A another B another C..., another use smartphones A another B another C..., the same with proxies, the same with the number of actions, the same with the niche, the content...
If you are serious, you have to keep in mind that there is no easy, simple, or cheap way... you need to test and adapt day by day.
The best thing is to always have your own test lab, that is, different small groups of accounts of different ages, followers, etc... with different proxies and do small/medium/large tests. It is the best advice I can give you.
When you buy accounts, you should first buy a few accounts and test them, each seller is different, they have different types of accounts. In your particular case, I think you're going fast, when you log in just browse at the beginning, no like, no follow, no comments... the slower the better. I also think you should try other proxies, as I said before, you have to try different things, for example: if you're going to buy 15 accounts, buy 5 of each kind and try 2 different proxies (providers) and get conclusions.
I think it´s better to start with more accounts and fewer actions and always warm up very slowly.