Those bugs have been adressed here -> [NLA] Alpha 1 - Resolution Issues and here-> Settlers randomly stop doing everything you can like their posts so developers known they are common bugs.
The official bug forum is here-> http://www.stonehearthguru.com/forums/alpha-beta-testing-nexus/support/bug-reports
You can comment there if you want. Maybe add your system information, although this bugs seem more a problem of optimization.