workers doesn't extract resources

if the game is configure to allow workers to extract resources from outside (like chop trees for example) on individual units (like tree-units) and if the unit that gives the resource is sorrounded (one worker in every direction) any other worker will remain doing nothing (they don't seek any other near free unit to extract)

also, if a resource depot is constructed and more than 8 workers are extracting, once the first eight would back from the depot, they will seek the nearest tree to extract, leaving the rest to wait, even if there any other tree nearby