15. SEGMENT INFORMATION (Details Narrative) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020	May 31, 2020	[1]
Operating lease right-of-use assets	$ 1,763		$ 1,763		$ 2,107
Five Largest Customers
Customers accounted for 10% or more of total revenues	95.00%	94.00%	82.00%	89.00%
Customer A
Customers accounted for 10% or more of total revenues	55.00%	71.00%	33.00%	51.00%
Customer B
Customers accounted for 10% or more of total revenues	15.00%		15.00%	18.00%
Customer C
Customers accounted for 10% or more of total revenues	11.00%		14.00%
Customer D
Customers accounted for 10% or more of total revenues	11.00%		11.00%

[1] The condensed consolidated balance sheet at May 31, 2020 has been derived from the audited consolidated financial statements at that date.