I think what is happening is that your iPhone is changing the plain text of the phone number into a clickable blue link, which on your blue background makes it look almost invisible.
It also looks like you have set the theme’s ‘Primary Color’ to a blue color (#0b1828) so the page links will be blue on blue background.
Not sure if the iOS/Safari phone link is blue because of the primary color setting or if Safari is defaulting links to blue color.
A couple of things to try
- explicitly change the color of the phone number text in the widget to white…
- …or if that doesn’t fix it, write the phone number with html markup to force it to display in white, see code below
<a href="tel:7754349967" style="color:#fff;">(775) 434-9967</a>