its a hardware fault short circuiting in the Rh clocks which they can't do anything about without visiting the satellites. Its not actually seen as a big problem because those clocks are backup.
The H clocks its something to do with the onboard monitoring and stabilisation system they don't know what it is and the work round is to control them from the ground, if they start stepping out they shut them down and reboot letting the RH clocks take over.
The 6 sats at the beginning don't have any problems the first 3 are now dead and the 4-6 are limited life span plus first gen hardware and systems.
So out of the 22 sats up there we are down to 16. two of which are out of orbit so that's 14..... All of which have the Rh hardware fault and 6 of them are down to 1 H clock. I think there are 2 with nothing failed.
It was meant to cost 3 billion, its now over 7 billion. If they said they would need to replace all 30 sats at 80 million a pop that would be 2.4 billion just for the hardware. last launch cost I saw was 25 million per unit but I don't know if that's a 4 at a time job which they are going for or singularly. So that would be in the region of 3.5 billion more.
even if you presume the 14 ones that are up there just now in the correct orbits will continue to work that's still another 16 satellites they need at 105 million each including launch at 1.7 billion.
I have no doubt politically they will go slow release, keep what's up there working ish and then feed in the "good" news later about the replacement units.
We shall see what happens from the stands.