Adding or editing a device in Safari (12.0.3 on MacOS 10.14.3 Beta, but this has been true for some months), Cacti 1.1.37, spins on "Contacting Device".
Error displayed in console seems to be "Error: Syntax error, unrecognized expression: #snmp_auth_protocol option[value="[None]"", but that may be unrelated.
Works correctly on Chrome 72.0.3626.53.