From the screenshot the vast majority of the gain is solar load, so I imagine there is glazing in this room? (If so, and if you wished to test, I would suspect that if this glazing was temporarily deleted this value would drop significantly).
The article below should also assist with clarifying load types:
CIBSE Gain Calculation - Load types - Hevacomp Wiki - Hevacomp - Bentley Communities
Regarding the casual load varying; you may have enabled a profile - if you wish a constant value then please ensure to untick the profile option as below:
Alternatively, you may just be seeing the hours of occupancy - the casual load will be applied to occupied hours only - ie as entered in the below:
Hope that helps to clarify.
Shane Regan | Principle Building Performance Support Engineer
Answer Verified By: John Moloney
Thanks for clarifying that Shane. I did indeed have the use profile box ticked for occupancy. I understand the convective and latent load are now resulting from air infiltration.
Great, glad to hear that helped. If you need anything else just let us know.