Same problem here 
Project with 6.6k inputs. I need to export about 60 orthoprojection. Random error during orthoprojection calculation. I have 128gb of ram. Ortho projection with 16500x6700 resolution consumes 110gb of ram. After the calculation is done, ram drops only to 80gb. So, there is obvious problem with RC not clearing the ram?
Didn’t have this problem with earlier build. Tried to clean temp and reseted the RC to factory default with no luck.