According to the microsectors website FNGA will be redeemedon 5/15/25. FNGB will be renamed back to FNGU on 6/2/25. It's pretty confusing but the bottom line is these are debt instruments that rely on interest rates so the funding costs changed and they to create a new ETN with new associated costs.
Thanks for the information... Not too many trade these etfs. I was short FNGU until I covered it around 365. Will go short again.