This isn't a bug (I've moved this to the Ideas board), as sorting is currently based on their internal ID number, which technically splits utilities differently than their subtype, instead basing it on their "effect type" (which uses a different order, since there are many dozens of effects, but a much smaller number of subtypes). That said, I do want to make adjustments to the sorting routine, which isn't yet complete, so I'll put this at the top of the list. I'll probably further rearrange their effect type ordering. (Internal ID order was also what was causing the earlier weapons-before-utilities sorting approach, which was changed in Alpha 9.)
Thanks for bringing it up, though, to make sure it makes it into Alpha 10 since this is an easy thing to change.
Anyone feel free to make part sorting feature requests, as it's new in Alpha 9 so this is the first everyone's had a chance to play with it.