Behaviours can be considered adaptive under certain conditions (as defined by evolutionary principles), but can be considered "non-adaptive" if the conditions under which they evolved change. For example consider an invasive species that is relocated to a new area and encounters new conditions, or adds a resource to the environment. There are even cases of what has been termed "an evolutionary trap" where f.e. native predator invests resources or reproductive effort into a prey/host resource that is actually unsuitable for consumption/parasitization. There is a good paper on egg parasitoids that deals with this if you are interested (Abram et al. 2013 Biol. Invasions DOI 10.1007/s10530-013-0576-y).

Causes of a "non adaptive behavior" can be related to a change in the environment that it is not tracked by a change in behavior. A classical example is the hedgehog's antipredatory strategy of rolling into a ball but it seems not very useful if you need to cross the road.