Time Machine backup from 13.5B2 client to 13.4 host creates new sparse bundle

System A = iMac running OS 13.4. (Time Machine host -- with 2 share pointed drives - call them A1 & A2) System B = iMac running OS 13.4 (Alternates backups to A1 and A2) System C = MacBook running OS 13.5B2 (Alternates backups A1 and A2)

I had to rebuild System A and reconfigure the sharepoints.

My problem is that now C is no longer binding with its respective "C.sparsebundle" files. Rather, it is creating new ones named "C_1.sparsebundle".

What, if anything, am I doing incorrectly?