Genetic divergence between Cape Lark and Agulhas Lark is rather shallow (and indeed, both species also are very little divergent from Eastern Long-billed Lark Certhilauda semitorquata) (Alström et al. 2013). With the caveat that there are few available audio recordings, vocalizations of the two also seem to be essentially identical (Boesman 2016). Therefore Agulhas Lark is lumped into Cape Lark.
https://www.birds.cornell.edu/clementschecklist/updates-corrections-october-2022/