Hopefully this is the correct place to post this, but I'm having a problem I've never experienced. Any "new connection" I make while on my computer is met with an initial 1-2 minutes of very high ping or lag. So any new game of fortnite I enter, any time I enter a new discord server, any new lobby of any online game I go into I am met with 600+ ping for anywhere from 1-3 minutes. After that initial period of lag it is completely fine, literally never have any other ping or lag spikes. I really don't know what to do first to try to fix this problem, I've called my ISP and they seem clueless. I'm really unfamiliar with fixing internet problems typically so I don't even know what I should be trying to check, but this problem is extremely frustrating.
Speedtesting while the "lag" was occuring, speeds seemed unchanged
All drivers up to date
Resetting modem/router multiple times
ISP: Verizon Fios
Speeds: 100mb/s down 100mb/s up
16gb 2133mhz ram
Gigabyte x99-sli motherboard
Edit: After talking to ISP more they assure me there is nothing on there end causing this issue.