After upgrading Supervisor Cluster to 1.27.10 no further updates are suggested. However, the query from tkr shows that there is also a version 1.28:
v1.28.7---vmware.1-fips.1-tkg.1 1.28.7+vmware.1-fips.1-tkg.1 True True.
This is a aesthetic issue, that will be sorted on future versions.
You can use kubectl edit to upgrade your tkc cluster.