Is something wrong with sntrup761x25519-sha512@openssh.com?

[PF4Public]

Since updating to dev-libs/openssl-1.1.1t-r1 and net-misc/openssh-9.2_p1-r2 i have weird ssh connectivity issues. Two systems (bare-metal Gentoo) cannot ssh into each other any longer. On them I cannot even ssh localhost! There is the third one (KVM-guest) which is 2 VPNs away from me and it shows no such issues. I can freely connect to it and from it (through aforementioned VPNs of-course). ssh localhost is also functioning there. I have another one (VMware-guest) 1 VPN away from me, which shows same symptoms. Am I doing something wrong?

Debug logs from sshd:

Code: Select all

debug1: kex: algorithm: sntrup761x25519-sha512@openssh.com [preauth]
debug1: kex: host key algorithm: ssh-ed25519 [preauth]
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none [preauth]
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none [preauth]
debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth]
debug3: receive packet: type 30 [preauth]
debug1: SSH2_MSG_KEX_ECDH_INIT received [preauth]
debug1: monitor_read_log: child log fd closed
debug3: mm_request_receive: entering
debug1: do_cleanup
debug3: PAM: sshpam_thread_cleanup entering
debug1: Killing privsep child 26732

Debug logs from ssh:

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debug2: compression ctos: none,zlib@openssh.com
debug2: compression stoc: none,zlib@openssh.com
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug1: kex: algorithm: sntrup761x25519-sha512@openssh.com
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
Connection closed by 127.0.0.1 port 22

"-oKexAlgorithms=-sntrup761x25519-sha512@openssh.com" solves the issue for me. But why is this happening?