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 lies 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 lies in Numbers 13:
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. Therefore, Scripture testifies that the spies were slandering (lying) when they reported what they saw in the land.
We can also see that their report was untrue by comparing their report to what we know Joshua found when the nation of Israel finally entered the land forty years later. When Joshua enters the land, the land of Canaan did not devour the nation of Israel as the spies reported it would. Furthermore, the men of Canaan were not giants in size, as the spies reported, nor were Nephilim found in the land.
Therefore, the report of Nephilim was not a truthful report. 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?