I just manually corrected the GUID(I know I know you’re not supposed to edit GUIDs, i took a backup first!) on one of the posts that wasn’t working and it fixed the problem straight away.
I changed it from something like:
[et_pb_section bb_built=”1″ admin_label=”section”]…
To something like:
Website_URL/?post_type=project&p=2576
Went back to the post, made a change, and it saved fine.
Any ideas as to why this could be? Also if anyone has a way of automating the correction of all the posts that are wrong, I’d appreciate it!!