Strange Comparison Issue

Day 2 of testing CF 2021 and I'm puzzled by what seems to be another bug.  Consider the following:  <CFSet A='147.xxx.yyy.zzz'> <CFOutput> #A#---<br> Left 4: #Left(A,4)#---<br> Left 4 eq: #iif(Left(A,4) eq '147.',DE('Yes'),DE('No'))#<br> Left 4 is: #iif(Left(A,4) is '147.',DE('Yes'),DE('No')...</cfoutput></cfset>