Why is this transaction unconfirmed after a few hours? https://blockstream.info/tx/8ede5096427abea7d7829aba85f491bb93d42aa4f9aa9dbd25f6862958c3609c
It says
ETA
in 4 blocks (13.24 vMB from tip)
Why is ETA in 4 blocks? What does it mean by 13.24 vMB from tip? What is the tip?
0.0000616 BTC (27.6 sat/vB)
My transaction fee is 27.6 sat/vB which seems to be high enough.
ETA in 4 blocks (13.24 vMB from tip). Why is ETA in 4 blocks?

Estimation by https://blockstream.info block explorer which is explained here: https://github.com/Blockstream/esplora/issues/262#issuecomment-706230773

What does it mean by 13.24 vMB from tip? What is the tip?

There are 13.24 vMB of transactions between your transaction and tip as shown in the below image from https://mempool.observer


My transaction fee is 27.6 sat/vB which seems to be high enough.

Fee rate above 100 sat/vByte would have been high enough looking at the mempool right now.

Fee rate distribution of all unconfirmed transactions. Source: https://btc.bitaps.com