Hi All,
Just to say, I found the issue for me was running WP 5.6.1
The inserter helper panel simply wouldn’t show. After days of Googling, trying different code, the default theme and no other plugins (except ACF), I tried rolling back on a whim
Once running 5.6, suddenly it started working again.
Hopefully, this may help someone else if they come across this thread
Cheers