Is anything incumbent upon me if I faltered after rising from bowing (rukuʿ) and said, "Allāh heard him who praised Him," then repeated the remembrance, "Allāh heard him who praised Him; our Lord, and to You be praise, good, blessed praise in it," while standing?

The position for "Tasmee'" (saying 'Sami'a Allahu liman hamidah'): between starting to rise from bowing (rukūʿ) and reaching the upright standing position. As for "Rabbana walakal-hamd" (Our Lord, to You be all praise), its place is after rising for the individual (munfarid) and the Imam, and during rising for the congregant (ma'mūm). The remembrance should not be prolonged until it is completed after reaching the upright position. If someone mistakenly recites "Tasmee'" twice in an incorrect place, there is no penalty, and prostration of forgetfulness (sujūd as-sahw) is recommended according to one opinion, but not recommended according to another.