It honestly depends on the issue at hand, as well as what browser they're using. For example, if they're using internet explorer, a browser that no longer runs or a super outdated version of a browser then I tend not to fix it as the amount of people using those specific browsers are slim to none and isn't worth the fix. However, if they're on opera or something and it's a major issue then I'll go through and try my best to make sure it works for that specific browser. It really just depends on how many people use that browser, and how vital the issue is.