Ik something similar but hope u find the actual fic https://archiveofourown.org/works/22128178/chapters/52816855
I searched around but never read it, it does mention a cane, so it's probably this.
https://archiveofourown.org/works/28058367/chapters/68740128
OHMGOFKERJGOJRWRWNJOOH MY GOF OH MYGOD OHMYOFD OHMUGFOD OHMUFODF OHUMOF YES YESYESYYES IT WAS THIS ONE THANK YOU UR A SAINT I LOVE YOU
^^ Enjoy!
NOT VERY MANGAGO RELATED BUTNIM TRHING TO FIND THIS FANFIC ON AO3 WHERE XIE LIAN WAS A FALLEN ACTOR AND LIKE HE HAD A CANE AND HUA CHENG WAS HIS CARETAKER LLEASE I LOVE IT SM IT WAS SMTH LIKE OLUCKING LAVENDAARS