Fresh install, can't log in due to SSLServerVerification, everything up to date

Hi, I signed up and tried running TeamSpeak 5 in Windows Sandbox first, but it just fails on SSL verification for whatever reason. Trying to load this URL in a browser (in and out of Sandbox) seems to contact the server fine, but gives no certificate, apparently, but I’m guessing it’s just supposed to be mTLS:
SSL certificate missing?

Log file:

[2025-01-19 00:04:51.557] [info] Notifications_Windows ctor
[2025-01-19 00:04:51.571] [info] TeamSpeak Client 5.0.0-beta77 (2023-12-12 11:58:52)
[2025-01-19 00:04:51.571] [info] SystemInformation: Windows 11 (26100) x64 (AMD or Intel) Binary: 64bit
[2025-01-19 00:04:51.701] [info] failed to load static integration list
[2025-01-19 00:05:15.469] [warning] Error contacting URL https://clientapi.myteamspeak.com/authentication: Canceled: SSLServerVerification

Everything is up-to-date and patched, and everything else that uses TLS is working just fine. The VM (and the host) have full internet connectivity, no proxies or extra NATs. Is the login server just down or is it from my end?