The FT-70D will save YSF rooms in its 5 room memories if there are no spaces or underscore characters, and all others are uppercase in the room name.
SSH into your pi-star and edit the YSF_Hosts file.
pi-star@pistar1(rw):~$ sudo nano /usr/local/etc/YSFHosts.txt
Remove any space or underscore ‘_’ characters in the room name of interest. Pi-star will change the lowercase characters for you so you don’t need to change them if you have ‘UPPERCASE Hostfiles:‘ turned on . eg. 00 CQ-UK WiresX becomes CQ-UK-WiresX.