What is the problem of my h1 tag on iphone?

Question

I have my mobile only website. I am testing on my Iphone 6. The problem is with my title h1 tag no showing when you load. It reappears after you resize the screen and scroll past it. Can anyone help? Please and Thanks. Code: https://github.com/SEGACD32XMODEL1/Websiteland/blob/master/mobile.html
Site: https://segacd32xmodel1.github.io/Websiteland/mobile.html

<span id="animationSandbox" style="display: block;">
<div id="grad1" id="topnav" class="myTopnav" class="site__title mega" style="text-align:center;margin:auto;color:#888888;font-size:6vh;font-weight:bold;font-family:oreos;line-height:0.5;overflow-wrap:anywhere;text-align:center;" height="150vh">
    <h1 class="site__title mega" style="overflow-wrap: break-word;text-align:center;padding-top:0px;line-height:16vh"> Websiteland <br>
        <div>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/Cornhub/index.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">Cornhub</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/Twitter/Crimeaday.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">Federal Crimes</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/main.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">GamesAndMore</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/KahootSpam/index.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">KahootSpam</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/index.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">Reload</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/RB420/index.html" class="site__title mega" style="font-family:oreos; font-size:2.5vw;line-height:1.5;">Roasted Beef 420</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/School/index.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">School</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/Time.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">Time</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/SpecialUnoCards.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">Uno Special Cards</a>
        <br>
        <a href="https://SEGACD32XMODEL1.github.io/Websiteland/Websites/index.html" class="site__title mega" style="font-family:oreos;font-size:2.5vw;line-height:1.5;">Websites</a>
        </div>
    </h1>
</div>