I obviously don't know if the hCaptcha is some hybrid offering of ebay.co.uk/hCaptcha that's specific to the UK but it doesn't always offer this "security measure" on ebay.co.uk, it's just when you do something to move from one part of your account to another, and usually, for now, only if I use Wayfarer with a User Agent as Safari (not Safari/iOS), Chrome, or Wayfarer itself.

Even now, using Wayfarer v2.2 I cannot use the Safari/iOS User Agent in Wayfarer as even that option has popped up as the same issue with this Security Measure with hCaptcha, so I can now no longer access my eBay account.

[UPDATE] - I just loaded Wayfarer v1.21, as an afterthought/double-check, to find that the hCaptcha mechanism works as it should with that version 1.21 , so the picture boxes/squares are generated correctly and can be completed, so it seems that somewhere the v2.2 or a version earlier has broken the way in which the hCaptcha works, and needs fixing.

Now I come to think of it I also had an issue with a couple of other websites (can't remember which at the moment) but probably some site that had strengthened security, for similar security issues ("Rate limited or network error. Please retry") with hCaptcha with version 2.2, so it probably is related to Wayfarer v2.2 being compromised internally regarding hCaptcha, and maybe some other web security issue(s).