Critical Pace settings

Hi team, I have noticed that, in my running plan, every time I enter a running critical pace that I think it’s correct, than it gets automatically changed to a pace that I can’t hold for more than 1000m, making me think that there is something wrong. How can I solve this issue?

Another problem I got is the fact that every time I set up my supposed critical pace the program rebuilt from start, prescribing me the same training sessions I’ve already done weeks ago. Can you help me out?

Thank you in advance