API method api/v0/transactions/send doesn't work properly

[GusevTimofey]

Problem: If client sends several (in my case 20) transactions where the next one depends on previous, explorer responses with 200 ok and tx id in a body for all requests, but only first N transactions (in my case 2-3) become available in node's mempool

How to repeat: Generate N where N > 5 transactions one depends on another. Next, sequentially send them to explorer, check mempool and which of them will appear in blockchain.