yeah gutenberg editor is a bit clumsy here.
You should be able to click – hold and drag the title bar of the Meta Box over the sidebar – for a marquee to appear for it to drop into. Its a tricky little bugger to find the right position though.
Thanks, David – no joy though. It is intensely annoying – I’ve tried at least 100 times to find this elusive “marquee” – any other tips to get it how it was? It’s not a deal-breaker, just annoying!