[2021] People suddenly disconnect from my games

Could you let me know what your connection’s upload speed is please @Jaywu? You could try using a website like https://www.speedtest.net/

Yes, your upload speed is very low. In the mean time you could try enabling the ‘Small Network Packets’ option in Vermintide 2’s ‘Network’ panel. But it would be infinitely better if your ISP could boost your upload speed somehow.