Does the fasting of one whose prayer has become invalid become invalid, or is prayer an independent act of worship separate from fasting?

Errors in prayer or ablution have no bearing on fasting, nor do they affect its validity. Not every error invalidates the prayer, and doubts after completing prayer or ablution should be disregarded. Whoever suffers from excessive doubts and obsessive thoughts should turn away from them and beware of exaggeration, over-scrupulousness, and extremism, for Satan may use this entry point to instill fear in a person about the inadequacy of their worship. These obsessive thoughts are dispelled by seeking refuge in Allah, adhering firmly to the truth, and repelling doubts.