Known Issues on PTR:

The PTR server is based in California, so you may experience lag depending on your geographic location.
Having addons such as wLauncher, Chaos Plugin, or others running will cause a crash. We recommend uninstalling addons to play 1.18.
Some players may experience a pause when selecting multiplayer. The issue is firewall related. If you do encounter a pause, please report how long the pause lasted, your system specs, and what firewall was triggered here.
Some computers’ firewalls will prompt to whitelist SC on every game launch when entering multiplayer.
Players cannot create private games with a non English password.
Vespene geyser has a graphical issue.
UTF-8 not supported in chat channels.