Same issue here:
/home/lagerspe/.spring/Zero-K.exe Information : 0 : Starting with version 1.3.2.119
/home/lagerspe/.spring/Zero-K.exe Information : 0 : UnitSync: Directory: /home/lagerspe/.spring/engine/100.0
/home/lagerspe/.spring/Zero-K.exe Information : 0 : UnitSync: ZKL: /home/lagerspe/.spring
/home/lagerspe/.spring/Zero-K.exe Error : 0 : Unhandled async exception: System.DllNotFoundException: unitsync
at (wrapper managed-to-native) ZkData.UnitSyncLib.UnitSync/NativeMethods:Init (bool,int)
at ZkData.UnitSyncLib.UnitSync..ctor (ZkData.SpringPaths springPaths) [0x00000] in <filename unknown>:0
at ZeroKLobby.Program+<>c.<Main>b__90_1 () [0x00000] in <filename unknown>:0
at ZkData.Utils+<>c__DisplayClass38_0.<StartAsync>b__0 (System.Object ) [0x00000] in <filename unknown>:0
/home/lagerspe/.spring/Zero-K.exe Information : 0 : UnitSync Disposed
/home/lagerspe/.spring/Zero-K.exe Warning : 0 : Failed to init VoiceCommands:Could not load file or assembly 'System.Speech, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies.
[S_API FAIL] SteamAPI_Init() failed; SteamAPI_IsSteamRunning() failed.
[S_API FAIL] SteamAPI_Init() failed; unable to locate a running instance of Steam, or a local steamclient.so.
/home/lagerspe/.spring/Zero-K.exe Information : 0 : Initial scan done
[S_API FAIL] SteamAPI_Init() failed; SteamAPI_IsSteamRunning() failed.
[S_API FAIL] SteamAPI_Init() failed; unable to locate a running instance of Steam, or a local steamclient.so.
Currently tested on laptop only, starts full screen, allows resizing, no issues like that, just cannot connect to server and cannot see any games.
The top bar button highlight is a bit weird, it has bright one color corners but otherwise a gradient.