bear is our resident expert
but i learned patience is very much needed and separation might be necessary during the transition period what i did try myself and what helped to some degree is this:https://www.amazon.com/gp/product/B01AVI1I06/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
one thing in your favor, both cats are young and should adjust
