Not sure if it plays any part, but asking just in case - what filtering are you using? The new High Quality filtering does blur things across more pixels, so just curious as to your settings there. It was present in Corona 4 as well as 5, but changed from a checkbox to part of the dropdown selection, so not impossible it was not enabled for you in 4, and is enabled in 5 (assuming that the same scene is not giving this problem in 4 as well, that is).
Anything else in use on the camera, any Film Offset or similar, that maybe wasn't used before?
Also, is this Max or C4D, which OS? May consider uploading the scene to our private uploader (see links in my signature) (looks like Max from the UI grab :) )