Hey Sizam, I thought I would give you an update after my deep-dive. During troubleshooting, I removed all plugins and tried with Child Theme. That didn't work. Switched to main Rehub Theme. This still had the bad behavior of menu on mobile. So, I did a fresh install of ReHub. Replaced the Child Theme. I applied this solution to resolve the problem which only seemed to occur when I changed the size of the window or looked at it on mobile. And it worked! Hope this helps.
/* ===== MOBILE MENU FIX: Rehub Off-Canvas ===== */
@media (max-width: 1024px) {
  /* Force vertical stacking and spacing */
  .off-canvas-active.menu {
    display: block !important;
    flex-direction: column !important;
    background-color: #fff;
    padding: 1rem;
  }
  .off-canvas-active.menu li {
    display: block;
    margin-bottom: 10px;
  }
  /* Ensure nested submenus are stacked */
  .off-canvas-active.menu .sub-menu {
    padding-left: 15px;
    border-left: 2px solid #ddd;
    margin-top: 5px;
  }
  /* Toggle icons (arrows) */
  .submenu-toggle {
    display: inline-block;
    float: right;
    font-size: 1rem;
  }
  /* Back button style */
  .back-mb {
    font-weight: bold;
    margin-bottom: 10px;
    cursor: pointer;
  }
  /* Make sure menu closes properly */
  .close-menu {
    display: block;
    text-align: center;
    margin-top: 15px;
  }
  /* Optional: limit max width for better appearance */
  .dl-menuwrapper {
    max-width: 100%;
    box-shadow: none;
    border: none;
  }
}
Geometry Dash is a fast-paced rhythm-based platformer where players jump, fly, and flip through challenging levels to the beat of energetic music.