Thanks for reaching out!
This sawtooth pattern shown in your screenshot is indicative of bandwidth saturation. Bandwidth saturation occurs when the inbound/outbound traffic exceeds what is actually available to you.
A couple of possible solutions to this can be either using less bandwidth (ex. not streaming Netflix while downloading a large file) or purchasing more bandwidth from your ISP (if possible).
You can learn more about diagnosing/understanding bandwidth saturation in the following articles. Diagnosing Bandwidth Saturation Bandwidth Saturation
If this leaves you with any questions let me know!