Why do you say it is not a styling issue – which is exactly what it sounds like?
Because it’s every number on the entire site, and there is no styling rule that can target just numbers or that can pull numbers out of a sentence to hide them (is there?). Like in the line “14 days” the word “days” shows up, but the number doesn’t. I can highlight and copy the word “days” but not the number, because it isn’t there. And it’s not just a specific tag, it’s all numbers everywhere.
I assume you do know that Safari on Windows has not been updated for a very long time and is, basically, abandoned.
No, I did not know that, but that is good to hear.
I can get someone who has access to Windows (but not 7) to look at it using the last Win Safari version available as I can’t as I am using Mac/OSX but you could start off by telling us what Simple:Press theme and overlay you are using so we can match it.
I’m using the Default theme with the black-gold overlay.
Edit: but it works fine on 8.1.