Hey there @Tau7ty6
Moved your post into this already existing topic which is the one summing up those issues. As explained in this topic, all S.A tutorials videos should be moved to a new server backbone infrastructure from their streaming content provider. As you can imagine, this simply can't happen overnight and it's going to take some time. Please check this specific post for more details.
An alternative way to watch content on YT or having to re-encode / re-upload all videos to offer different quality settings would take edges & is not a satisfying long term solution IMHO. Most of the time, resuming the video playback or playing back the video from start will solve the buffering issues, which is of course annoying but the real issue is for users that can't even watch the content, this seems to especially affect users in the Pacific region. In such case, S.A can proceed to a refund as explained in the above mentioned post.
For all other users that are experiencing buffering problems, please be patient and let's wait for a proper solution that will fix this issue for everyone