Hi Ellery
If you still have this problem I suggest you open a case with Support.
As you know the device and password management databases are separate, so it may happen that the complexity of the search you are doing causes some performance issues. Hence we should look at this from support.
In any case, if this is still a problem you could try to narrow it down by doing a complex search that involved just password management objects on one side, and another one for devices. That may help us determine if it is one or the other database. Still, as mentioned this warrants a support case.
Best regards