I'm so frustrated with crafting with Recombinator. Is it bugged?

I tried recombine one item with fracture with not fractured base and
when i want to get base without fracture (clearing out fracture) i get fractured base 10/10 (item levels allow for choosing both), and with another mods/case, when i need to get fractured part with not fractured it chooses the opposite.

How this game mechanic works? How should i understand that without reading whole internet and several scientific papers on reddit?
(https://www.reddit.com/r/PathOfExile2/comments/1jzu2py/poe_2_patch_020_guide_to_recombinators_part_1/#:~:text=You%20can't%20select%20a%20fractured%20modifier.%20However%2C,base%20is%20kept%2C%20the%20fractured%20mod%20stays.)

In game it says "choose random". while it seems thats its not

I lost so much currency already, and i dont have any idea how crafting works with recombinator, should i include recombinator in this process, or it is unga bunga bugged or im just super unlucky man ?