Basically it means that we can't regard the Hubble result as a mismeasurement and the age of the universe seems to be different depending on how you measure it.
From the article:
"The bottom line is that the so-called Hubble Tension between what happens in the nearby Universe compared to the early Universe’s expansion remains a nagging puzzle for cosmologists. There may be something woven into the fabric of space that we don’t yet understand."