YouTube video rapidly Buffers (pauses and unpauses)

My partner has been experiencing an issue where when we go to watch a YouTube video, the video will buffer on her end, but not mine. The buffering occurs for about a second before skipping forward to where I am in the video and constantly cuts out the audio so she can’t hear the video and can only watch it at 1 frame per second. At first, we thought this was a connection issue, however, we have tried when she is both connected to a wifi source and when she is using mobile data. It can’t be her mobile device because it used to work just fine on the same phone. she is using an android. Please let me know if you know how to resolve this issue. Thanks.

Thanks for your feedback. I would need to know a bit more about that device and the browser in use. Can she visit https://www.whatismybrowser.com/ and email me the unique link that the site provides at the top to florian@watch2gether.com - Thanks!