They were told they would not get another interim approval for this year in 2020. There are many issues with the system. Obviously they have an issue they have been unable to, or refused to fix for years. In my opinion the only reason they got as many interim approvals as they did, was because the CEO was in front of every camera and politician he could find saying how his aircraft would save the world. Had it not been for COVID, they would have not received an interim approval last year.
The issues with the aircraft are not well publicized, but are well known to the aviation community.
The ground compressor, necessitates flying all the way back to one single base for reload. Potentially flying over multiple bases capable of handling the aircraft. Increasing cost and decreasing efficiency.
The aircraft has continually come back to base with large quantities of retardant still in the tank. Anywhere from 3000-9000 gallons.
The aircraft releasing the load at below approved heights was the cause of a line of duty death in 2018 on the Mendocino complex.
The pattern created by the tanker was not consistent and would create weak spots in the line.