Intermittent loading of reCaptcha

I’ve seen this a few times on sites we maintain and haven’t noticed a pattern. We’ve had complaints from our customers about their contact forms not working, which they have replicated. When I’ve gone to their forms, most of the time every thing is fine, but occasionally I’ve spotted that the recatpcha is missing. The header is there, but the box isn’t there.

It’s as if the call to render it failed perhaps? You then can’t submit the form at all. If you reload the page, the captcha appears properly and all is fine.

I haven’t spotted if this is a V2 or V3 issue. The site linked is V2 and we’ve a bit of a mix across our sites.

This is obviously a massive showstopper as people willing in the form will have no idea that it should be there so have no reason to reload the page ??

The page I need help with: [log in to see the link]