db.c.drop()
// This must be done in mongo shell, not mongosh which will convert undefined to null
db.c.insert({a: undefined})
db.runCommand({analyze: 'c', key: 'a'})
db.adminCommand({setParameter: 1, planRankerMode: "histogramCE"})
db.c.find({a: 1})

Error: error: {
    "ok" : 0,
    "errmsg" : "Error getting histograms for path test.c : aString bsonUndefined is not convertable to SBE type tag.",
    "code" : 6660600,
    "codeName" : "Location6660600"
}