In your Genesis teaching, you taught that the Nephilim in Chapter 6 all died in the Flood, but the ten spies claimed to see Nephilim in the land after the Exodus. How could the spies have seen Nephilim in Canaan if they all died in the flood?
The report of the ten spies was not a truthful report. Scripture confirms that the unfaithful spies delivered a bad report to Moses and the people, because they were afraid they would die in trying to take the land as God directed. We read of their attempt in Numbers 13:
Num. 13:31 But the men who had gone up with him said, “We are not able to go up against the people, for they are too strong for us.”
Num. 13:32 So they gave out to the sons of Israel a bad report of the land which they had spied out, saying, “The land through which we have gone, in spying it out, is a land that devours its inhabitants; and all the people whom we saw in it are men of great size.
Num. 13:33 “There also we saw the Nephilim (the sons of Anak are part of the Nephilim); and we became like grasshoppers in our own sight, and so we were in their sight.”
In v.32 scripture says the sons of Israel give a "bad report." The word for bad in Hebrew is dibbah, which literally translates as defamation or slander. You can find the same Hebrew word used Psalms 31:13 and in Proverbs 10:18. Slander is a lie intended to harm, and this is what the spies delivered.
Since we know the Nephilim all died out in the flood, therefore their report of Nephilim was not a truthful one. It was a lie designed to convince the Israelites to remain outside the land. For this lie and their unbelief, the spies along with that generation of Israel were condemned to die in the desert.
You may also be interested in the following question: How did fallen angels and humans produce Nephilim?