I am not sure you are interpreting the law about Levites owning land correctly.
Joshua 10 describes the division of the land between the tribes, but does not assign it to individuals. Verse 14 gives no portion of the land to Levi:
Only to the tribe of Levi he had given no inheritance; the sacrifices of the Lord God of Israel made by fire are their inheritance, as He said to them.
It is not that individual Levites had no inheritance. The tribe did not have a region of the promised land set aside for them. Instead, they were distributed amongst the cities in other tribes' land.
Consider Numbers 35:1-2:
In the plains of Moab by the Jordan at Jericho, the Lord spoke to Moses, saying: Command the Israelites to give, from the inheritance that they possess, towns for the Levites to live in; you shall also give to the Levites pasture lands surrounding the towns.
Along with these cities, the Levites were given fields around those cities.
And in Deuteronomy 18:6-8, we see that not only could individual Levites have an inheritance, they could sell it:
So if a Levite comes from any of your gates, from where he dwells among all Israel, and comes with all the desire of his mind to the place which the Lord chooses, then he may serve in the name of the Lord his God as all his brethren the Levites do, who stand there before the Lord. They shall have equal portions to eat, besides what comes from the sale of his inheritance
And Nehemiah 13:10:
I also realized that the portions for the Levites had not been given them; for each of the Levites and the singers who did the work had gone back to his field.
It seems that as least in the time of Nehemiah, Levites could own fields as part of the support offered to them.