Intermittent display problem with CustomPress Field

Hi

We've got CustomPress running on our site and are experiencing intermittent display issues in the following way. Basically, the content block will show correctly on events like this;

http://www.greenwichmums.com/events/2016/10/free-fun-golf-event-kids-american-golf-greenwich-peninsula/

http://www.greenwichmums.com/events/2017/02/baby-childrens-market-charlton-house-2/

and this ...

http://www.greenwichmums.com/events/2016/10/big-bike-ride-2/

BUT NOT on other events like this...

http://www.greenwichmums.com/events/2016/10/makerversity-half-term-academy-farmopolis-4/

All use Events+ and the same shortcode.

Can you help please? It's probably - and hopefully - a quick fix, but it escapes me.

Thanks

James.

ps - I've granted you guys access to have a closer look.