Here is the summary:
Ladybug cumulative radiation uses gendaymtx.
Honeybee cumulative radiation uses gencumulativesky.
Honeybee annual daylight is using Daysim which is using gencumulative sky.
Honeybee[+] annual daylight is using Radiance and gendaymtx.
Based on this topic the issue can be because of the weather data. Gencumulativesky had a known issue for low sun angle calculation which was fixed while ago but if possible I suggest using gendaymtx. We’re removing all the dependencies to gencumulativesky in the [+] libraries.