I just thought it was weird that that the other transaktion got close to 100 confirmations in the same time, with almost the same fee.
But it only comes down to the fee? There's nothing else impacting time it takes?
Miners have the last say in including any transactions in their block. It is totally possible that miners don't really like your transaction and chose to ignore it all the way. It can also be due to poor propagation though I doubt that is actually a factor in this, seems to be pretty well propagated from what I can tell.
If your other transaction pays the similar fees/size, it may be due to miner selecting your transaction as the last to be included in their block (assuming that they organise the transaction based on the fees/size).