On Saturday, 13 July 2024 02:26:41 BST Ionen Wolkens wrote:
> On Sat, Jul 13, 2024 at 04:11:05AM +0400, Vitaly Zdanevich wrote:
> > We had nothing bad in our conversations...
> 
> From the whole server, not a channel? Don't know what happened but it
> wouldn't be Gentoo-specific then given Gentoo doesn't run IRC servers
> nor is part of the Libera staff.

According to the Libera FAQs:

"The server says I am banned! Why?

If you are unable to connect to the network and have received a message that 
you are banned, first ensure that you are using SASL as sometimes we need to 
restrict some IPs to require the SASL authentication method. This requires you 
to have registered an account already. Use another internet connection to make 
an account first, if you’re unable to connect on your regular internet 
connection.

If you are still unable to connect, or if you get banned again once you do 
connect, you can enquire about the ban by sending an email to us at 
bans@libera.chat."

https://libera.chat/guides/faq#the-server-says-i-am-banned-why

It's probably a temporary ban, perhaps you were caught into some geographic IP 
range during a DDoS.