It happened that I observed something sticky on back of my foot before sleeping at night. I became mujnib while sleeping and did ghusl before seher. However after time of Namaze Fajr had commenced I remembered that sticky thing and it was still there. Is my ghusl valid? Is my fast in order? Then I read Namaze Fajr, is it valid? Do I need to redo ghusl or do qaza of fast & Namaz.

If that sticky things was not removed from you feet and it was barrier for water to teach your skin but then you realized after finishing your salat and you were aware about that thing was there on your feet, your salat and fast is ok but for other namaz you have to do Ghusl again.