I recently enabled IPv6 on my router and added Tencent and Ali IPv6 DNS. However, I've noticed a few issues with my network. Specifically, when opening videos on Bilibili, the screen goes black for 3 seconds before loading, and the playback is slow with frequent 'loading' prompts. Additionally, when scrolling to the comments section, it takes another 3 seconds to load. I've tried restarting the router and disabling DNS to resolve the issue, but neither solution worked. Curiously, restarting the modem improved the situation. I'm wondering what might be causing this problem.