164 point drop on ClearScore but no change on Statutory credit report or Experian

Randomly got notified my report changed on Clearscore, advising a drop of 164 points but not saying any reason why this happened as it usually does if a score changed, but when I check my score on Experian, it says it's excellent (which it should be, I only use paypal credit, pay it off along with my mortgage every month and have no other issues/debts or anything of the sort) Just really confused as I know credit should never drop for no reason, ClearScore is showing as 399 drop from 569 whereas Experian is showing as 979/999 and nothing out of the ordinary on my statutory report from TransUnion in the UK?

All this to say I don't actually care what the number is itself, more so just what caused the significant 164 point hit?