Websockets maximum packet length

[king2]

Hello!

I have a problem with websockets with relatively large packets. When message size grows to something about 570-580 bytes - problems begins.

Size of message received by client, for example, is 583 bytes. When React sends something back (same message, but modified a bit) - 538 bytes. Receive 594 bytes - 549 goes back, and so on, some information losts. 577 bytes data and less - works as it should.

Another fact is that when I click on button, message sent to server highlights with green color in DevTools.
With little packets such green messages disappears much faster than with large messages.

But if I quick enough to copy outgoing green message from DevTools - it looks like normal JSON.

Can you help me with this problem?
Thanks!