Thanks for the bug report, should be fixed now. You might wanna reload the game with Ctrl+F5 to make sure it loads the new version and does not take the old version from your browser cache. The build number in the bottom of the Settings menu should say 2017 now.
For the unit pathfinding: I know it's pretty terrible right now. Problem is that I have pretty much no CPU budget at all to compute paths (javascript isn't that fast and there is no multi-threading...) Maybe I can improve it a little bit.