Auto-select choosing a number of non-functional servers and failing when there are working servers close by

[natzlob]

Running the command with auto-select server option, the test tries a number of servers that do not work and then the test fails.
Here is the verbose output:

Selecting the fastest server based on ping
Error checking for server status: Get "https://il1.us.backend.librespeed.org/empty.php": dial tcp 134.195.89.225:443: connect: connection refused
Server Chicago, United States (HostHatch) (il1.us.backend.librespeed.org) doesn't seem to be up, skipping
Error checking for server status: Get "https://fc81600e6362286791bf6e06fb9d1cd4.librespeed.de/backend/empty.php": dial tcp: lookup fc81600e6362286791bf6e06fb9d1cd4.librespeed.de: no such host
Server Frankfurt, Germany (active-servers) (fc81600e6362286791bf6e06fb9d1cd4.librespeed.de) doesn't seem to be up, skipping
Server Frankfurt, Germany (Clouvider) (fra.speedtest.clouvider.net) doesn't seem to be up, skipping
Error checking for server status: Get "http://speedtest.linkedtech.es/backend/empty.php": dial tcp: lookup speedtest.linkedtech.es: no such host
Server Madrid, Spain (Linked Tech Network) (speedtest.linkedtech.es) doesn't seem to be up, skipping
Error checking for server status: Get "https://lv1.backend.librespeed.nixnet.services/empty.php": remote error: tls: internal error
Server Las Vegas, United States (BuyVM) (lv1.backend.librespeed.nixnet.services) doesn't seem to be up, skipping
Error checking for server status: Get "https://la1.us.backend.librespeed.org/empty.php": dial tcp 185.198.26.89:443: connect: connection refused
Server Los Angeles, United States (2) (HostHatch) (la1.us.backend.librespeed.org) doesn't seem to be up, skipping
Error checking for server status: Get "https://ny2.us.backend.librespeed.org/empty.php": dial tcp 134.195.90.126:443: connect: connection refused
Server New York, United States (3) (HostHatch) (ny2.us.backend.librespeed.org) doesn't seem to be up, skipping
No ICMP pings returned for server Helsinki, Finland (3) (Hetzner) (finew.openspeed.org), trying TCP ping
Error checking for server status: Get "https://lux1.backend.librespeed.nixnet.services/empty.php": remote error: tls: internal error
Server Roost, Luxembourg (BuyVM) (lux1.backend.librespeed.nixnet.services) doesn't seem to be up, skipping
No ICMP pings returned for server Poznan, Poland (INEA) (speedtest.kamilszczepanski.com), trying TCP ping
Server Tokyo, Japan (A573) (librespeed.a573.net) doesn't seem to be up, skipping
Server West Europe (Azure) (ls.sergiomeloni.com) doesn't seem to be up, skipping
Error checking for server status: Get "http://in1.backend.librespeed.org/empty.php": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
Error checking for server status: Get "http://nl1.backend.librespeed.org/empty.php": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
Server Bangalore, India (DigitalOcean) (in1.backend.librespeed.org) doesn't seem to be up, skipping
Server Alblasserdam, Netherlands (RamNode) (nl1.backend.librespeed.org) doesn't seem to be up, skipping
Error checking for server status: Get "https://sxb.bandspeed.de/backend/empty.php": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
Server Strasbourg, France (Host Europe) (sxb.bandspeed.de) doesn't seem to be up, skipping
Selected server: Alblasserdam, Netherlands (RamNode) [nl1.backend.librespeed.org]
Sponsored by: RamNode @ https://www.ramnode.com/
Error checking for server status: Get "http://nl1.backend.librespeed.org/empty.php": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
Selected server Alblasserdam, Netherlands (RamNode) (nl1.backend.librespeed.org) is not responding at the moment, try again later

I am running this test from Cape Town, South Africa. There is a server in Johannesburg that works perfectly. If I specify to use that server, the test works

Selected server: Johannesburg, South Africa (Host Africa) [za1.backend.librespeed.org]
Sponsored by: HOSTAFRICA @ https://www.hostafrica.co.za
You're testing from: 197.93.145.238 - Dimension Data, ZA (1270 km)
Ping: 42 ms	Jitter: 11 ms
Download rate:	19.03 Mbps
Upload rate:	66.12 Mbps

How does the test choose the order in which servers are tried and why does it stop trying when there are, in fact, working servers?