禁用 Web 浏览器的 CGI 脚本缓冲

我有一个用 Perl 编写的小型 CGI 脚本，它以 1 秒的间隔打印从 1 到 10 的数字：

root@debian-s-1vcpu-1gb-fra1-01:~# cat /usr/lib/cgi-bin/test
#!/usr/bin/perl

use strict;
local $|=1;

print "Content-encoding: none\nContent-type: text/plain\n\n";
#print "Content-type: text/plain\n\n";

for ( my $i = 1 ; $i <= 10 ; $i++ ) {
    print "$i\n";
    sleep(1);
}
root@debian-s-1vcpu-1gb-fra1-01:~#

该脚本在使用时按预期工作curl：

但是，对于 Web 浏览器（例如 Chromium 88.0.4324.182 或 Firefox 78.13.0esr），页面加载 10 秒，然后立即显示从 1 到 10 的数字。Web 浏览器的请求和响应标头如下所示：

即使我使用与上面示例curl相同的请求标头执行Firefox，数字也会以 1 秒的间隔打印，因为它们应该：

$ curl -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'Accept-Encoding:
gzip, deflate' -H 'Accept-Language: en-US,en;q=0.5' -H 'Connection: keep-alive' -H 'Host: 164.90.236.255' -H 'Upgrade-Insecure-Requests: 1' -H 'User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0' -v http://164.90.236.255/cgi-bin/test
* Expire in 0 ms for 6 (transfer 0x55b238016fb0)
*   Trying 164.90.236.255...
* TCP_NODELAY set
* Expire in 200 ms for 4 (transfer 0x55b238016fb0)
* Connected to 164.90.236.255 (164.90.236.255) port 80 (#0)
> GET /cgi-bin/test HTTP/1.1
> Host: 164.90.236.255
> Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
> Accept-Encoding: gzip, deflate
> Accept-Language: en-US,en;q=0.5
> Connection: keep-alive
> Upgrade-Insecure-Requests: 1
> User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0
>
< HTTP/1.1 200 OK
< Date: Mon, 24 Jan 2022 12:19:56 GMT
< Server: Apache/2.4.25 (Debian)
< Content-encoding: none
< Keep-Alive: timeout=5, max=100
< Connection: Keep-Alive
< Transfer-Encoding: chunked
< Content-Type: text/plain
<
1
2
3
4
5
6
7
8
9
10
* Connection #0 to host 164.90.236.255 left intact
$ 

服务器已Apache 2.4.25禁用mod_deflate。

什么可能导致这种行为？如何在 Web 浏览器中禁用 CGI 脚本缓冲？也许有一个响应头允许人们控制这种行为。