Submit button and Recaptcha disappeared

Hi there
Using the most recent version of the plugin, although this problem occurred in 1.7.2, then I updated to no effect. The website owners reported today that the Submit button has disappeared on this form https://www.swimbournemouth.org.uk/join/free-trial-for-swim-bournemouth.html. It isn’t only the button, the Recaptcha field above it is also gone. Can you suggest any reason why this might be?

Thanks

https://www.ads-software.com/plugins/wordpress-form-manager/