I did some quick tests ...
OK: I have the pop-up list after typing @S ,( got "Susan" ,"Super Admin") on the CB demo site ,
KO: In every case it works only if I type
@S [backward] S , If i delete the @ , i must restart
With Google Chrome : KO on PC Windows 11, KO on tablet Android 15, KO on smartphone Android 16
With Firefox : KO on PC Windows 11 ,
OK on tablet Android 15 , OK on smartphone Android 16
With Samsung Internet : KO on smartphone Android 16
fyi, I tried also with virtual keyboard ( no change in behavior)
Yes, that's Odd , it's a minor issue but user must be aware of this ( it's took a while for me to understand why i cannot use @mention
)