The Condorcet system I am familiar with allow for ties between choices of preference.
For example, three choices A, B and C.
a valid ballot can be cast for A = B, which puts both of them 1 vote ahead of C.
that's the opposite of a single preference showing a vote for C, which puts C 1 vote ahead of both A and B.
These are both valid opinions and both should be permitted.
Here's a very old web page that allows Condorcet voting using ties: