While inspecting requests where Content-Length > 3000, only 3000 characters of the request body gets displayed in both Raw and Text views. When I copy the whole contents of the selectable area (CMD + A, CMD + C) and paste it into a text editor, it seems like there is a 'View full request...' text somewhere which does not show up. I remember this button from previous versions.
OS : macOS Mojave Version 10.14.6
A sample HTML with dummy form to reproduce the bug and recorded session is attached.