This often happens to me when opening the free WOF on my email on my PC especially on Chrome browser however it works fine on other browsers such as edge or firefox. This is an easy fix, just try to refresh it or open it on other browsers. Also, spinning on your phone might work as I never encountered that issue when opening WOF on my phone. The issue may be on the captcha itself on your browser which is why you can't spin on the WOF.
I also think for a while it's better to do another alternative that can be done, actually you don't need to use another browser but just use a private browser it seems it's working fine, maybe it's because the slow internet makes the captcha not load properly
Weirdly, this doesn't work on me especially when I've been doing a lot of captchas on a day as they keep getting harder to load than usual. Not sure, if this only applies on my situation but those are his options if he ever gets to encounter the same issue again.