Subscribing to several order books takes too long

[giust]

Hi,

I'm subscribing to many orderbooks at once (more than 100) using this sample code

const book100 = await kraken.ws.book({depth: 100})
// live book construction from "snapshot", "ask", and "bid" events.
.on("mirror", (mirror, pair) => console.log(mirror, pair))
.on("error", (error, pair) => console.log(error, pair))
// resubscribes if there is a checksum validation issue (emits statuses).
.on("status", (status) => console.log(status)
.subscribe("XBT/USD", "ETH/USD", .....); // subscribe to multiple pairs at once

Most of them subscribe within a few seconds, but a few take some minutes. Any idea what could be causing this delay?

Thank you