Open Targets takes an exact id for a direct lookup and free text for a search, and the two are different queries. This is what tells them apart.
References
Buniello et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research 53(D1), D1467-D1475. doi:10.1093/nar/gkae1128
Service documentation: https://platform.opentargets.org/