Bot on VK-IO responds slowly in conversations, why?

Question

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Good afternoon, there is a bot on VK-IO. In private messages, he responds quickly (1-2 seconds), and if you add him to the conversation and write to him there, he will answer in the region of 10 seconds (the bot has an admin panel in the conversation). Why is this happening? The command consists in the usual sending of a simple message.
I will be glad if you help, thanks.

Answer 1

It turns out that VK itself was lagging. I leave it for those who will face a similar problem.