SecureLine VPN - Fast upon connecting, then slows down 70-80%

I have 1000/40 mbps service from Spectrum. When VPN first connects I get full speed as measured by Ookla Speedtest windows app. After a few minutes it slows down to 200-300/40 mbps.

If I disconnect and reconnct the speed returns to 1000/40 mbps, but then after a few minutes it slows down again.

I can repeat this cycle.

Thank you!