This article contains some steps to solve the buffering issue. And, how to share feedback if it doesn't work, so that we can help you fix it.
Frequent buffering during playback
Frequent buffering can occur when the viewer’s Internet bandwidth does not support playback of the selected video quality. Try switching to “Auto” in the quality menu (the default), if available. If “Auto” is not available, switch to one of the lower quality options.
How can you share your speed test results with us, if your video still fails to start?
1) Check your estimated bandwidth at https://testmy.net/download
2) After the test is finished, copy and send us the Result URL on the top left as shown in the screenshot.