ReCaptcha weird behaviour

Hello.

Just noticed a weird behaviour of Google’s ReCaptcha, v2.
In an Omeka Classic site that’s using a (little) customized Berlin theme, the Contat Us plugin’s page spots the ReCaptcha in the wrong position (see picture below).

ReCaptcha v2 style used is “Invisible” (and, still, it appears); I’m waiting for who’s in charge of retrieving the secret keys to try switching to “I’m not a robot” style, as in other sites using that style the ReCaptcha’s behaviour is normal.

Has anybody experienced anything similar? And any alternative solution suggested?
Thanks.