tiktok live stream video lagging how do i stop? (its not my internet)

I need to know if anybody else has had this problem. So ive been trying to stream for that past 3 days only to be met with extremely low upload speeds?? Like it will go from over 3+ mbps a second to only 200 khps for like 10-15 mins then correct itself???? ive tried testing my internet speed while it was "lagging" and it i was getting over 250 mbps.. so im not sure wtf could be causing this. Also the video is the only thing lagging, the audio is fine.