Youtube intentionally adding some lines to their videos

Today I've noticed some horizontal lines on youtube videos. Upon further investigation, I've traced it to a single div element: <div class="ytp-gradient-bottom" style="height: 296px; background-image: url(&quot;data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAEoCAYAAACZwZvDAAAAQklEQVQ4T2Ow67zNyeC6YGM/Q+EkM0cG0a23CxgyjyjXMbTXLD7BUHZK8R7D8Z83axlG1Y2Gy2g6GM0fo+XBoCwnAS2Ics8DLkccAAAAAElFTkSuQmCC&quot;);" data-layer="9"></div> The base64 encoded image is the lines I'm seeing. Initially after starting a new private session and navigating straight to youtube.com I had no lines. Then in that private session same element doesn't have an image: <div class="ytp-gradient-bottom" data-layer="9" style=""></div> What's odd about this is if I opened a private window and copy pasted the same video URL I would get the lines. After testing multiple times I started getting the lines even after navigating straight to youtube.com. So I did another test: changed my IP with a VPN in a private session. Navigated straight to youtube.com, watched multiple videos without any lines. Then I logged in to my account and boom, the lines are back... Opening the same video on google chrome browser I get a smooth gradient line image: <div class="ytp-gradient-bottom" data-layer="9" style="height: 194px; background-image: url(&quot;data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAADCCAYAAACIaaiTAAAAAXNSR0IArs4c6QAAARJJREFUOE9lyNdHBQAAhfHb3nvvuu2997jNe29TJJEkkkgSSSSJJJJEEkkiifRH5jsP56Xz8PM5gcC/xfCIWBNHiXiTQIlEk0SJZJNCiVRIM+mUyDCZlMgy2ZTIMbmUyDP5lCgwhZQoMsWUKDGllCgz5ZSogEpTRYlqU0OJoKmlRJ2pp0SDaaREk2mmRItppUSbaadEh+mkRBd0mx5K9Jo+SvSbAUoMmiFKDJsRSoyaMUqMmwlKhMwkJabMNCVmYNbMUSJsIpSImnlKLJhFSiyZZWoFVmEN1mEDNmELtmEHdmEP9uEADuEIjuEETuEMzuECLuEKruEGbuEO7uEBHuEJnuEFXuEN3uEDPuELvuEHfv8AoRErEi7Uc8UAAAAASUVORK5CYII=&quot;);"></div> The browser is functioning as intended, but youtube is intentionally making their website unusable. What the f###? I have youtube premium, adblocker disabled on their website.