I got a bit fed up of Medium. There’s something about the format that encourages long articles structured in a particular way. I found it very limiting and realised it was stopping me from writing anything at all. It also started to feel very click-baity to get people to pay the monthly subscription and I wasn’t finding anything worth reading. So I’ve moved everything back to WordPress.
In case you’re thinking of doing the same, I found that the best way of migrating all my posts was to open a free account on WordPress.com and use their Medium importer. I then exported everything from there in WordPress format (actually in two goes because the maximum file size is 2Mb) and then used the WordPress importer on my own installation of WordPress here. Took me a while to work out but I think everything has moved successfully.