hi,
to become able to recognize correlated results or to spot possible problematic signals, you need training and experience. difficult to help you much with theoretical statements. we should look at your results together and then we could give you some suggestions.
however, here some general hints:
+ it is correct to check that the peaks of the estimated parameters are centered at zero, in this way you make sure your reference point is adequate
+ check the APS final test (the coherence in space and time after integration of the estimated parameters and removal). if the coherence is high and homogeneous in space and time, this is the best sign that everything went well and that you can trust the estimated APS
+ if the test did not go well, you can play a bit with the non-linear weights hoping to stabilize in this way the spatial integration. however, this is a delicate operation and you need some experience to modulate it correctly
best