Okay thanks for letting me know. If you want to attempt fixing, the relevant function is called InputField in the UI class. Specifically this code:
foreach (char c in InputHelper.InputStringThisFrame)
{
bool invalidChar = char.IsControl(c) || char.IsSurrogate(c) || char.GetUnicodeCategory(c) == System.Globalization.UnicodeCategory.Format;
if (invalidChar) continue;
state.TryInsertText(c + "", validation);
}