I think mycelium needs to improve the way it calculates fees. I submitted a transaction with the "normal" fee. It took an hour to get the first confirmation.
d75f3a16f84351a7cb23e24c0b082b8acb5ce4bc33f28fbe5a77a738842020bb
There were 50 minutes without a block at that time.
That just happens, 10 minutes between blocks is only the average, it can sometimes be faster or slower.
Would be interesting to know how many sigma off the mean that 50 minutes was.