Contradiction with Numbers 11:9
This verse mentions manna descending with the dew at night, rather than appearing only after the dew evaporates as stated in Exodus 16:14.
Numbers 11:9: And when the dew fell upon the camp in the night, the manna fell upon it.
Contradiction with John 6:31
This verse refers to manna as bread from heaven, which can be interpreted as a contradicting view of its appearance and form compared to the small round thing described in Exodus 16:14.
John 6:31: Our fathers did eat manna in the desert; as it is written, He gave them bread from heaven to eat.