Hello Poompt, I would like to apologize for all the trouble you had faced with your NUC.
Please let me know how are you trying to roll back the BIOS to version 028?
Have you tried doing a BIOS recovery? Desktop Boards — Instructions for Recovery BIOS Update
In case the issue persisted and if the NUC is still under warranty, please get in touch with our Warranty team in order to replace it Contact Support or submit a web ticket at the following URL Service Request Email