I have a young 4 year old female lab that has developed a serious no go problem on blinds. She needs one more pass for her Master Hunter title. Until 5 weeks ago she never had this problem. Then on the last series of a MH Test she refused to go on "Back" for a relatively simple double blind, max distance 120 yards. She has been trained on difficult blinds ranging from passing poison birds up to 400 yards, handles very well and has been the best of three dogs I have trained. The following day she gave a no go on land blinds in the first series. The following day she gave a no go in the second series of the Q field trial. Three weeks later she gave another no go in the second series water blinds in a MH test. I later ran the same blinds using a collar to make sure she went. She got the first 125 yard water land blind with one handle and lined the second 90 yard blind.
She has been force fetched, forced to pile, etc. Although I train with an E collar, I almost never use it because she does so well and wants to please. I do notice she may appear to be confused on the above no gos but can not understand why since she routinely runs much more difficult blinds.
I would appreciate any suggestions on how to resolve this problem.