I do have Mycelium installed, but I use it watch-only, didn't actually make transactions with it.
However, the fees are not written as numbers, or at least I didn't find such a setting. The setting I've found allows you select between Low-Prio, Economic, Normal and Priority.
That's just the setting options for the fee range it will "default" to when you actually create a transaction (ie. the position of the "top" slider)... if you look on the the "send transaction" screen, you get a LOT more options! However, the fees are not written as numbers, or at least I didn't find such a setting. The setting I've found allows you select between Low-Prio, Economic, Normal and Priority.
You can slide the top slider between the four "Low-Prio, Economic, Normal and Priority", and each of those has 6-8 fee options...
Unfortunately, it still seems to calculate the available options based on current fee rates... so you can end up with the "lowest" fee being higher than 1 sat/byte... I just took this screenshot now, and the lowest is 3 sats/byte
