Can confirm it is for me at least. After sending emails through every channel I could find, I got an emailed reply from CS last night advising the issue was resolved and asking me to try again.

Last night it was half there - points balance now visible again, and all that, but couldn't see card details nor history (entire Loyalty Card tab missing)

This morning though it's back to normal.

Just such a shame it comes basically one day after the Sept 10k pts promotion ended. And while Hilton are running triple points...