The development team is well aware of the current issues the testers are experiencing while playing the beta release. Most importantly the latency issues caused by military personel attempting to target mutiple zombies at once. Works are underway to release a patch resolving this issue along with various other small bugs fixes and map patch-ups.
We'll keep everybody informed as more information becomes availiable. Stay up-to-date on progress of upcoming patches @
http://steamcommunity.com/app/346330/discussions/10/494632338493827220/
or
https://reperio-studios.net/threads/known-issues.439/