I believe they’re referring to the “crisis in cosmology”. I’m purely a layman, but I found some videos useful. I believe at least PBS Space-Time [1] is well regarded in physics circles (for laymen explanations.). I found the other one [2] to be more digestible though.
[1] https://youtu.be/72cM_E6bsOs
[2] https://youtu.be/0sfvQ_fsil4