Internet Download, Upload, and Latency Speeds Consistently drop to below usable levels from 7pm till past midnight every day

I've been having an issue where the download, upload, and latency speeds consistently drop to below usable levels every night, and only during the night. I've gone through the AI chatbot troubleshooting steps multiple times and it constantly sends me a back on a loop of restarting gateway and telling me that the internet is good when it is verifiably not. A tech has previously come out, but the problem immediately started again after he left the next day. I'm unable to play any online games as my latency is above 280+ms consistently after getting home from work.