AXFR gets stuck downloading ch from the public sources

Summary

Downloading public .ch gets stuck on 9.20

BIND version affected

9.20.1, 9.20.2 and bind-9.20 branch

Steps to reproduce

Use named.conf below and start named.

What is the current bug behavior?

The transfer is not progressing.

What is the expected correct behavior?

The transfer should be progressing.

Relevant configuration files

options {
	recursion no;
	notify explicit;
	max-transfer-idle-in 1;
	max-transfer-time-in 5;
};

# filename ch_zonedata.key
key tsig-zonedata-ch-public-21-01 {
    algorithm hmac-sha512;
    secret "stZwEGApYumtXkh73qMLPqfbIDozWKZLkqRvcjKSpRnsor6A6MxixRL6C2HeSVBQNfMW4wer+qjS0ZSfiWiJ3Q==";
};

# filename li_zonedata.key
key tsig-zonedata-li-public-21-01 {
    algorithm hmac-sha512;
    secret "t8GgeCn+fhPaj+cRy1epox2Vj4hZ45ax6v3rQCkkfIQNg5fsxuU23QM5mzz+BxJ4kgF/jiQyBDBvL+XWPE6oCQ==";
};

zone "ch" {
	type secondary;
	primaries { 86.119.29.94 key "tsig-zonedata-ch-public-21-01"; };
	file "zones/ch";
};

zone "li" {
	type secondary;
	primaries { 86.119.29.94 key "tsig-zonedata-li-public-21-01"; };
	file "zones/li";
};

Relevant logs

20-Sep-2024 12:21:17.660 zone li/IN: Transfer started.
20-Sep-2024 12:21:17.664 zone ch/IN: Transfer started.
20-Sep-2024 12:21:17.696 0x7f9988c29000: transfer of 'ch/IN' from 86.119.29.94#53: connected using 86.119.29.94#53 TSIG tsig-zonedata-ch-public-21-01
20-Sep-2024 12:21:17.696 0x7f9989a29000: transfer of 'li/IN' from 86.119.29.94#53: connected using 86.119.29.94#53 TSIG tsig-zonedata-li-public-21-01
20-Sep-2024 12:21:21.160 zone li/IN: transferred serial 2024092012: TSIG 'tsig-zonedata-li-public-21-01'
20-Sep-2024 12:21:21.160 0x7f9989a29000: transfer of 'li/IN' from 86.119.29.94#53: Transfer status: success
20-Sep-2024 12:21:21.160 0x7f9989a29000: transfer of 'li/IN' from 86.119.29.94#53: Transfer completed: 1113 messages, 369691 records, 16815902 bytes, 3.464 secs (4854475 bytes/sec) (serial 2024092012)
20-Sep-2024 12:22:47.724 0x7f9988c29000: transfer of 'ch/IN' from 86.119.29.94#53: maximum idle time exceeded: timed out
20-Sep-2024 12:22:47.760 zone ch/IN: Transfer started.
20-Sep-2024 12:22:47.796 0x7f9988c29a00: transfer of 'ch/IN' from 86.119.29.94#53: connected using 86.119.29.94#53 TSIG tsig-zonedata-ch-public-21-01
20-Sep-2024 12:24:17.820 0x7f9988c29a00: transfer of 'ch/IN' from 86.119.29.94#53: maximum idle time exceeded: timed out
20-Sep-2024 12:24:21.764 zone ch/IN: Transfer started.
20-Sep-2024 12:24:21.808 0x7f9988c2a400: transfer of 'ch/IN' from 86.119.29.94#53: connected using 86.119.29.94#53 TSIG tsig-zonedata-ch-public-21-01
20-Sep-2024 12:24:51.764 0x7f9988c2a400: transfer of 'ch/IN' from 86.119.29.94#53: failed while receiving responses: timed out
20-Sep-2024 12:24:51.764 0x7f9988c2a400: transfer of 'ch/IN' from 86.119.29.94#53: Transfer status: timed out
20-Sep-2024 12:24:51.764 0x7f9988c2a400: transfer of 'ch/IN' from 86.119.29.94#53: Transfer completed: 23230 messages, 7045020 records, 340183007 bytes, 29.956 secs (11356089 bytes/sec) (serial 2024092012)

There's more stuff being wrong - the named gets stuck on shutdown after the timeout.