Slow internet speed on macbook M3

[Vatashi]

Hello! My kaspersky VPN is very slow on my macbook pro M3 with macos Sonoma v.14.5 although it works relatively fast on my old macbook pro with macos Catalina v.10.15.7. For example, when I switch on to the fastest server (Poland-Warsaw), the download/upload speed is 7Mbps/2Mpbs on macos Sonoma and 30mbps/11mbps on macos Catalina (two macbooks work simultaneously). The original internet speed is about 100mbps. Same happens with any other location. I cannot find the reason for that. What happens? What's wrong? Can you help me to solve this?