There is bug where when you are attuned to two elements and you mount and dismount, you will end up with skill bar that has skills 1, 2, 4 and 5 from primary element and 3 being a mixed skill.
For a long time I tought that this bug happend just randomly after mounting, but today I noticed that it happends when you quickly swap attunements and then mount up right after.
https://youtu.be/bf-kBG-cwBk
Would love to see it getting fixed at some point.