In the episode All Good Things in the future time period the Pasteur fires a tachyon beam which originates the anomaly. It is an Anti-time anamoly so grows backwards in time and not forward. So when the Enterprise commanded by Admiral Riker returns to the spot there should not be any anomaly visible.

The Riker Enterprise is ahead in time of the creation of the anomaly and the anomaly only grows backwards in time so once they created it they should never see it unless they travel backwards in time which they don't.

~~~~ Unless Q hid it as part of the test.

Early in the episode 'caretaker' when tom paris is being transported to ds9 the number on the side of the shuttle reads 71325 but after the pilot explains about voyager the shuttle number changes to 1701-D

Chekov assaults And incapacitates Kang as he and his wife are walking through the corridor of the enterprise together. Chekov then under control of the alien being sexually assaults Kangs wife where he is presumably still laying unconscious. During the assault Kirk happens upon it and intervenes. He ask Kangs wife to be taken to Kang to explain things to him all the while the show doesn’t reference the fact Kang should still be on the floor right in front of them!