The golden rail powered up abnormally

Under normal circumstances, the power-up distance of a golden rail will not exceed 9 blocks. However, when I placed a detector rail at the end of a series of golden rails, the power-up distance increased abnormally: all the golden rails from the signal source to the detector rail were all powered up. This abnormal power-up can extend up to 16 blocks. When I updated next to the detector rail, this abnormal power-up immediately disappeared.

The attached pictures and videos can illustrate this point. The video might be a bit hard to understand because my English pronunciation is poor. But still, I hope it will be helpful.

 

Expected:

The power-up distance of a golden rail will not exceed 9 blocks in all situation.

 

Actually:

The power-up distance of a golden rail will extend to up to 16 blocks in the situation see above.

 

P.S. the video is highly compressed, so it will look blurred. plz don't mention that.