Note: This issue only occurs when using "Markdown Mode". Only U.S. based brands have this option. We encourage everyone to use the "Rich Text Mode" when editing text.
Heavy punctuation—particularly a lot of parentheses and hyperlinks—sometimes gets confused as markdown syntax. If you've entered a block of text and some of it is disappearing in preview, you likely have to "escape" the markdown.
Typically, this can be solved by putting a backslash in front of each of the last set of parentheses, like this: \( lorem ipsum \).
Before: sun may lead to liver spots (a.k.a. age spots)
After: sun may lead to liver spots \(a.k.a. age spots\)
Check in preview to see that your text has reappeared. If it hasn't, let us know!