see Bug 71974
https://bugs.documentfoundation.org/show_bug.cgi?id=71974
and expecially take a look at
https://bugs.documentfoundation.org/show_bug.cgi?id=71974#c4
https://bugs.documentfoundation.org/show_bug.cgi?id=71974#c8
an easy edit of the standard non emoji fraction replacements will solve this old Calc autocorrect collision